Elections and Variables to the 1994 ISDA Credit Support Annex To the Schedule to the ISDA Master Agreement dated as of January 22, 2008 between Party A and Party B dated as of

EXHIBIT 10.6 — CREDIT SUPPORT ANNEX

Elections and Variables

to the 1994 ISDA Credit Support Annex

To the Schedule to the ISDA Master Agreement dated as of January 22, 2008

between Party A and Party B

dated as of

January 22, 2008

between

This Annex supplements, forms part of, and is subject to, the ISDA Master Agreement referred to above (this “Agreement”), is part of its Schedule and is a Credit Support Document under this Agreement with respect to each party.

Accordingly, the parties agree as follows:

Paragraphs 1-12. Incorporation

Paragraphs 1 through 12 inclusive of the ISDA Credit Support Annex (Bilateral Form) (ISDA Agreements Subject to New York Law Only) published in 1994 by the International Swaps and Derivatives Association, Inc. are incorporated herein by reference and made a part hereof.

Paragraph 13.

The term “Obligations” as used in this Annex includes the following additional obligations: None.

“Threshold” means with respect to Party B: infinity.

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A Custodian will be entitled to hold Posted Collateral on behalf of Party B pursuant to Paragraph 6(b); provided that:

(1) Posted Collateral may be held only in the following jurisdiction: United States.

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(2) The Custodian for Party B shall (A) be a commercial bank or trust company which is unaffiliated with Party B and organized under the laws of the United States or state thereof, having assets of at least $500 million and (i) a long term debt or a deposit rating of at least Baa2 from Moody’s and (ii) a short term rating of at least A-1 from S&P (or if it does not have a short term rating from S&P, a long term debt or a deposit rating of at least A+ from S&P), and (B) hold all Eligible Credit Support in a collateral account segregated from any other accounts of Party B or any other Person, including any other collateral account related to Swap Agreement with a Swap Counterparty other than Party A.

(3) Initially, the Custodian for Cash and Securities for Party B is: The Indenture Trustee under the Indenture, or any successor trustee thereto. If at any time the Custodian does not have a short term rating of at least A-1 from S&P (or if it does not have a short term rating from S&P, a long term debt or a deposit rating of at least A+ from S&P), Party B must within 60 days obtain a replacement Custodian with at least such rating from S&P.

Party A: To be notified to Party B by Party A at the time of the request for the transfer.

Party B: To be notified to Party A by Party B upon request by Party A.

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Notwithstanding Paragraph 10, the Pledgor will be responsible for, and will reimburse the Secured Party for, all transfer and other taxes and other costs involved in the transfer and maintenance of Eligible Credit Support either from the Pledgor to the Secured Party or from the Secured Party to the Pledgor.

The rights, powers and remedies of the Secured Party under this Annex shall be in addition to all rights, powers and remedies given to the Secured Party by the Agreement or by virtue of any statute or rule of law, all of which rights, powers and remedies shall be cumulative and may be exercised successively or concurrently without impairing the rights of the Secured Party in the Posted Credit Support created pursuant to this Annex.

“Credit Support Amount” shall be (a) in respect of S&P, the S&P Credit Support Amount and (b) in respect of Moody’s, the Moody’s First Trigger Credit Support Amount, or the Moody’s Second Trigger Credit Support Amount, as applicable.

With respect to Moody’s:

“Moody’s First Trigger Credit Support Amount” means, for any Valuation Date, the excess, if any, of

For the purposes of this definition, the “Moody’s Additional Collateralized Amount” with respect to any Transaction shall mean:

if Moody’s First Trigger Credit Support Amount is calculated using DV01, the lesser of (x) the product of the Moody’s First Trigger DV01 Multiplier and DV01 for such Transaction and such Valuation Date and (y) the product of Moody’s First Trigger Notional Amount Multiplier and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; and

if Moody’s First Trigger Credit Support Amount is calculated without using DV01, the product of the applicable Moody’s First Trigger Factor set forth in Table 1 and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; or

“First Trigger Failure Condition” means that no Relevant Entity has credit ratings from Moody’s at least equal to the Moody’s First Trigger Required Ratings.

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“DV01” means, with respect to a Transaction and any date of determination, the sum of the estimated change in the Secured Party’s Exposure with respect to such Transaction that would result from a one basis point change in the relevant swap curve on such date, as determined by the Valuation Agent in good faith and in a commercially reasonable manner. The Valuation Agent shall, upon request of Party B, provide to Party B a statement showing in reasonable detail such calculation.

“Moody’s First Trigger DV01 Multiplier” means (A) if each Local Business Day is a Valuation Date, 15, or (B) otherwise, 25.

“Moody’s First Trigger Notional Amount Multiplier” means (A) if each Local Business Day is a Valuation Date, 2%, or (B) otherwise, 4%.

“Moody’s Second Trigger Credit Support Amount” means, for any Valuation Date, the excess, if any, of

For the purposes of this definition:

“Next Payment” means, in respect of each Next Payment Date, the greater of (i) the amount of any payments due to be made by Party A under Section 2(a) on such Next Payment Date less any payments due to be made by Party B under Section 2(a) on such Next Payment Date (in each case, after giving effect to any applicable netting under Section 2(c)) and (ii) zero.

“Next Payment Date” means each date on which the next scheduled payment under any Transaction is due to be paid.

“Moody’s Additional Collateralized Amount” with respect to any Transaction shall mean:

if such Transaction is not a Transaction-Specific Hedge,

if Moody’s Second Trigger Credit Support Amount for a fixed schedule swap is calculated using DV01the lesser of (i) the product of the Moody’s Second Trigger DV01 Multiplier and DV01 for such Transaction and such Valuation Date and (ii) the product of the Moody’s Second Trigger Notional Amount Multiplier and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; and

if Moody’s Second Trigger Credit Support Amount for a fixed schedule swap is calculated without using DV01the product of the applicable Moody’s Second Trigger Factor set forth in Table 2 and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; or

if such Transaction is a Transaction-Specific Hedge,

if Moody’s Second Trigger Credit Support Amount for a fixed schedule swap is calculated without using DV01, the lesser of (i) the product of the Moody’s Second Trigger Transaction-Specific Hedge DV01 Multiplier and DV01 for such Transaction and such Valuation Date and (ii) the product of the Moody’s Second Trigger Transaction-Specific Hedge Notional Amount Multiplier and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; and

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if Moody’s Second Trigger Credit Support Amount for a Transaction-Specific Hedge is calculated without using DV01the product of the applicable Moody’s Second Trigger Factor set forth in Table 3 and the Notional Amount for such Transaction for the Calculation Period which includes such Valuation Date; or

(B) for any other Valuation Date, zero, over

“Transaction-Specific Hedge” means any Transaction that is an interest rate cap, interest rate floor or interest rate swaption, or an interest rate swap if (x) the notional amount of the interest rate swap is “balance guaranteed” or (y) the notional amount of the interest rate swap for any Calculation Period otherwise is not a specific dollar amount that is fixed at the inception of the Transaction.

“Second Trigger Failure Condition” means that no Relevant Entity has credit ratings from Moody’s at least equal to the Moody’s Second Trigger Ratings Threshold.

“Moody’s Second Trigger DV01 Multiplier” means (A) if each Local Business Day is a Valuation Date, 50, or (B) otherwise, 60.

“Moody’s Second Trigger Transaction-Specific Hedge DV01 Multiplier” means (A) if each Local Business Day is a Valuation Date, 65, or (B) otherwise, 75.

“Moody’s Second Trigger Transaction-Specific Hedge Notional Amount Multiplier” means (A) if each Local Business Day is a Valuation Date, 10%, or (B) otherwise, 11%.

“Moody’s Second Trigger Notional Amount Multiplier” means (A) if each Local Business Day is a Valuation Date, 8% or (B) otherwise, 9%.

With respect to S&P:

“S&P Credit Support Amount” means, for any Valuation Date, the excess, if any, of:

(I) for any Valuation Date on which (a) a Collateralization Event with respect to S&P has occurred and been continuing (i) for at least 10 Local Business Days or (ii) when this Annex was executed and (b) a Ratings Event with respect to S&P has not occurred and been continuing for at least 10 Local Business Days, the excess, if any, of (A) an amount equal to the aggregate Secured Party’s Exposure for such Valuation Date with respect to all Transactions, over (B) the Threshold for Party A for such Valuation Date, or

(II) for any Valuation Date on which a Ratings Event with respect to S&P has occurred and been continuing for at least 10 Local Business Days, the excess, if any of (A) an amount equal to the product of (x) the aggregate Secured Party’s Exposure for such Valuation Date with respect to all Transactions, and (y) 125%, over (B) the Threshold for Party A for such Valuation Date, or

(III) for any other Valuation Date, zero.

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All demands, specifications and notices under this Annex will be made pursuant to the Notices Section of this Agreement, save that any demand, specification or notice:

If to Party A:

As set forth in Part 4(a) of the Schedule.

If to Party B:

As set forth in Part 4(a) of the Schedule.

or at such other address as the relevant party may from time to time designate by giving notice (in accordance with the terms of this subparagraph) to the other party;

Party A and Party B agree that, notwithstanding anything to the contrary in the first sentence of this Annex, Paragraph 1(b) or Paragraph 2 or the definitions in Paragraph 12, except with respect to Party B’s obligations under Paragraph 3(b), (a) the term “Secured Party” as used in this Annex means only Party B, (b) the term “Pledgor” as used in this Annex means only Party A, (c) only Party A makes the pledge and grant in Paragraph 2, the acknowledgement in the final sentence of Paragraph 8(a) and the representations in Paragraph 9 and (d) only Party A will be required to make Transfers of Eligible Credit Support hereunder.

(k) Limitation of Liability. It is expressly understood and agreed by the parties hereto that (i) this Annex is executed and delivered by the Owner Trustee not individually or personally but solely as Owner Trustee of the Trust, in the exercise of the powers and authority conferred and vested in it, (ii) each of the representations, undertakings and agreements herein made on the part of the Trust is made and intended not as a personal representation, undertaking or agreement by the Owner Trustee but is made and intended for the purpose of binding only the Trust, (iii) nothing herein contained shall be construed as creating any liability on the part of the Owner Trustee, individually or personally, to perform any covenant either expressed or implied contained herein, all such liability, if any, being expressly waived by the parties hereto and by any Person claiming by, through or under the parties hereto and (iv) under no circumstances shall the Owner Trustee be personally liable for the payment of any indebtedness or expenses of the Trust or be liable for the breach or failure of any obligation, representation, warranty or covenant made or undertaken by the Trust under this Annex.

[Signature page follows]

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IN WITNESS WHEREOF, the parties have executed this document by their duly authorized officers with effect from the date specified on the first page hereof.

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Table 1

Moody’s First Trigger Factor

If “Valuation Date” means each Local Business Day, the “Daily Collateral Posting” column will

apply and the Weekly Collateral Posting Column will be deleted.

If “Valuation Date” means the first Local Business Day in each week, the “Weekly Collateral

Posting” column will apply and the Daily Collateral Posting Column will be deleted.

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Table 2

Moody’s Second Trigger Factor for Interest Rate Swaps with Fixed Notional Amounts

If “Valuation Date” means each Local Business Day, the “Daily Collateral Posting” column will

apply and the Weekly Collateral Posting Column will be deleted.

If “Valuation Date” means the first Local Business Day in each week, the “Weekly Collateral

Posting” column will apply and the Daily Collateral Posting Column will be deleted.

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Table 3

Moody’s Second Trigger Factor for Transaction-Specific Hedges

If “Valuation Date” means each Local Business Day, the “Daily Collateral Posting” column will

apply and the Weekly Collateral Posting Column will be deleted.

If “Valuation Date” means the first Local Business Day in each week, the “Weekly Collateral

Posting” column will apply and the Daily Collateral Posting Column will be deleted.

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Annex A

13

Annex B

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