What is the change in sales in 2018?
{"": {"Fiscal 2018": "", "Fiscal 2017": "(in millions)", "% Change": ""}, "Sales": {"Fiscal 2018": 207.0, "Fiscal 2017": 168.9, "% Change": 23.0}, "Operating loss": {"Fiscal 2018": -0.1, "Fiscal 2017": -9.3, "% Change": -99.0}, "Adjusted EBITDA": {"Fiscal 2018": 26.2, "Fiscal 2017": 14.4, "% Change": 82.0}}
sales_fiscal_2018 = df["Sales"]["Fiscal 2018"]
sales_fiscal_2017 = df["Sales"]["Fiscal 2017"]
answer = sales_fiscal_2018 - sales_fiscal_2017