What is the difference in franchise revenues between 2017 and 2018?
{"Company restaurant sales": {"2019": "$\u2014", "2018": 192620.0, "2017": 436558}, "Franchise revenues": {"2019": "\u2014", "2018": 9337.0, "2017": 20065}, "Company restaurant costs (excluding depreciation and amortization)": {"2019": "\u2014", "2018": -166122.0, "2017": -357370}, "Franchise costs (excluding depreciation and amortization)": {"2019": "\u2014", "2018": -2338.0, "2017": -4993}, "Selling, general and administrative expenses": {"2019": 174.0, "2018": -19286.0, "2017": -36706.0}, "Depreciation and amortization": {"2019": "\u2014", "2018": -5012.0, "2017": -21500}, "Impairment and other charges, net": {"2019": -262.0, "2018": -2305.0, "2017": -15061.0}, "Interest expense, net": {"2019": "\u2014", "2018": -4787.0, "2017": -9025}, "Operating (loss) earnings from discontinued operations before income taxes": {"2019": -88.0, "2018": 2107.0, "2017": 11968.0}, "(Loss) gain on Qdoba Sale": {"2019": -85, "2018": 30717.0, "2017": "\u2014"}, "(Loss) earnings from discontinued operations before income taxes": {"2019": -173.0, "2018": 32824.0, "2017": 11968.0}, "Income tax benefit (expense)": {"2019": 2863.0, "2018": -15726.0, "2017": -4518.0}, "Earnings from discontinued operations, net of income taxes": {"2019": 2690.0, "2018": 17098.0, "2017": 7450.0}, "Net earnings per share from discontinued operations: -- Basic": {"2019": 0.1, "2018": 0.6, "2017": 0.24}, "Net earnings per share from discontinued operations: -- Diluted": {"2019": 0.1, "2018": 0.59, "2017": 0.24}}
franchise_revenues_2017 = df["Franchise revenues"]["2017"]
franchise_revenues_2018 = df["Franchise revenues"]["2018"]
answer = franchise_revenues_2017 - franchise_revenues_2018