Amendment No. 6 to Revolving Credit Agreement between ProAssurance and U.S. Bank National Association, Wells Fargo Bank, National Association, Branch Banking and Trust Company, First Tennessee Bank, N.A., and JP Morgan Chase Bank N.A., filed as an Exhibit to ProAssurance's Annual Report on Form 10-K for the Year ended December 31, 2019 (File No. 001-16533) and incorporated herein by reference pursuant to SEC Rule 12b-32