. these notes may be redeemed prior to maturity at any time in whole or in part at the option of the company at a 201cmake-whole 201d redemption price . the unamortized discount and debt issuance costs are being amortized over the remaining term of the 2019 notes . 2017 notes . in september 2007 , the company issued $ 700 million in aggregate principal amount of 6.25% ( 6.25 % ) senior unsecured and unsubordinated notes maturing on september 15 , 2017 ( the 201c2017 notes 201d )