What is the percentage change in the amortization of issuance costs from 2018 to 2019?
{"": {"June 30, 2019": "", "June 24, 2018": "(in thousands)", "June 25, 2017": ""}, "Contractual interest coupon": {"June 30, 2019": 100712, "June 24, 2018": 77091, "June 25, 2017": 95195}, "Amortization of interest discount": {"June 30, 2019": 3937, "June 24, 2018": 12225, "June 25, 2017": 22873}, "Amortization of issuance costs": {"June 30, 2019": 1426, "June 24, 2018": 2034, "June 25, 2017": 2414}, "Effect of interest rate contracts, net": {"June 30, 2019": 4086, "June 24, 2018": 3, "June 25, 2017": -4756}, "Total interest cost recognized": {"June 30, 2019": 110161, "June 24, 2018": 91353, "June 25, 2017": 115726}}
amortization_2019 = df["Amortization of issuance costs"]["June 30, 2019"]
amortization_2018 = df["Amortization of issuance costs"]["June 24, 2018"]
answer = ( amortization_2019 - amortization_2018 ) / amortization_2018 * 100.0