What is the change in the amount of sales from 2018 to 2019?
{"": {"Fiscal 2019": "", "Fiscal 2018": "(in millions)", "% Change": ""}, "Sales": {"Fiscal 2019": 317.9, "Fiscal 2018": 325.2, "% Change": -2.0}, "Operating income": {"Fiscal 2019": 23.0, "Fiscal 2018": 16.6, "% Change": 39.0}, "Adjusted EBITDA": {"Fiscal 2019": 32.8, "Fiscal 2018": 26.3, "% Change": 25.0}}
sales_fiscal_2019 = df["Sales"]["Fiscal 2019"]
sales_fiscal_2018 = df["Sales"]["Fiscal 2018"]
answer = sales_fiscal_2019 - sales_fiscal_2018