What was the percentage change in Comprehensive earnings between 2017 and 2018?
{"Net earnings": {"2019": 36146, "2018": 46532, "2017": 14448}, "Other comprehensive earnings (loss): -- Changes in fair market value of derivatives, net of tax": {"2019": -509, "2018": 795, "2017": 110}, "Other comprehensive earnings (loss): -- Changes in unrealized pension cost, net of tax": {"2019": 6439, "2018": -1830, "2017": 13687}, "Other comprehensive earnings (loss): -- Cumulative translation adjustment, net of tax": {"2019": 83, "2018": -311, "2017": 437}, "Other comprehensive earnings (loss): -- Other comprehensive earnings (loss)": {"2019": 6013, "2018": -1346, "2017": 14234}, "Other comprehensive earnings (loss): -- Comprehensive earnings": {"2019": 42159, "2018": 45186, "2017": 28682}}
comprehensive_earnings_2018 = df["Other comprehensive earnings (loss): -- Comprehensive earnings"]["2018"]
comprehensive_earnings_2017 = df["Other comprehensive earnings (loss): -- Comprehensive earnings"]["2017"]
answer = (comprehensive_earnings_2018 - comprehensive_earnings_2017) / comprehensive_earnings_2017 * 100.0