What was the change in the Other comprehensive earnings  between 2017 and 2019?
{"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}}
other_comprehensive_earnings_loss_2019 = df["Other comprehensive earnings (loss): -- Other comprehensive earnings (loss)"]["2019"]
other_comprehensive_earnings_loss_2017 = df["Other comprehensive earnings (loss): -- Other comprehensive earnings (loss)"]["2017"]
answer = other_comprehensive_earnings_loss_2019 - other_comprehensive_earnings_loss_2017