Company’s option, (a) the Eurocurrency Rate (as defined in the Credit Agreement) plus 1.75% or (b) the Base Rate (as defined in the Credit Agreement) plus 0.75%.
On June 25, 2021, the Company entered into Amendment No. 11 to the Credit Agreement, pursuant to which lenders thereunder have provided the Company an additional $215,000,000 in aggregate principal amount under the Term A Facility. The Company used the net proceeds from the increase in the Term A Facility (together with cash on hand), to (i) redeem all of the Company’s remaining 5.875% Senior Notes due 2024 and (ii) pay fees and expenses related to such redemption.
At September 30, 2022 and 2021, letters of credit totaled $4.4 million and $5.2 million, respectively, under the Company’s Revolving Credit Facility. As of September 30, 2022 and 2021, the Company had $1,145.6 million and $1,144.8 million, respectively, available under its revolving credit facility.
2027 Senior Notes
On February 21, 2017, the Company completed a private placement offering of $1,000,000,000 aggregate principal amount of its unsecured 5.125% Senior Notes due 2027 (the “2027 Senior Notes”). On June 30, 2017, the Company completed an exchange offer to exchange the unregistered 2027 Senior Notes for registered notes, as well as related guarantees.
As of September 30, 2022, the estimated fair value of the 2027 Senior Notes was approximately $930.0 million. The fair value of the 2027 Senior Notes as of September 30, 2022 was derived by taking the mid-point of the trading prices from an observable market input (Level 2) in the secondary bond market and multiplying it by the outstanding balance of the 2027 Senior Notes. Interest is payable on the 2027 Senior Notes at a rate of 5.125% per annum. Interest on the 2027 Senior Notes is payable semi-annually on March 15 and September 15 of each year, commencing on September 15, 2017. The 2027 Senior Notes will mature on March 15, 2027.
At any time and from time to time prior to December 15, 2026, the Company may redeem all or part of the 2027 Senior Notes, at a redemption price equal to 100% of their principal amount, plus a “make whole” premium as of the redemption date, and accrued and unpaid interest to the redemption date. On or after December 15, 2026, the Company may redeem all or part of the 2027 Senior Notes at a redemption price equal to 100% of their principal amount, plus accrued and unpaid interest on the redemption date.
The indenture pursuant to which the 2027 Senior Notes were issued contains customary events of default, including, among other things, payment default, exchange default, failure to provide notices thereunder and provisions related to bankruptcy events. The indenture also contains customary negative covenants.
The Company was in compliance with the covenants relating to the 2027 Senior Notes as of September 30, 2022.
Other Debt and Other Items
Other debt consists primarily of obligations under capital leases and loans, and unsecured credit facilities. The Company’s unsecured credit facilities are primarily used for standby letters of credit issued in connection with general and professional liability insurance programs and for contract performance guarantees. At September 30, 2022 and 2021, these outstanding standby letters of credit totaled $640.3 million and $478.5 million, respectively. As of September 30, 2022, the Company had $427.4 million available under these unsecured credit facilities.
Effective Interest Rate
The Company’s average effective interest rate on its total debt, including the effects of the interest rate swap agreements and excluding the effects of prepayment premiums included in interest expense, during the years ended September 30, 2022, 2021 and 2020 was 3.8%, 4.4% and 5.3%, respectively.
Interest expense in the consolidated statements of operations included amortization of deferred debt issuance costs for the years ended September 30, 2022, 2021 and 2020 of $4.9 million, $10.2 million and $5.4 million, respectively.
9. Derivative Financial Instruments and Fair Value Measurements
The Company uses interest rate derivative contracts to hedge interest rate exposures on the Company’s variable rate debt. The Company enters into foreign currency derivative contracts with financial institutions to reduce the risk that its cash flows and earnings