What was the change in gearing ratio from 2018 to 2019?
{"Borrowings, current portion": {"2018": 520550.0, "2019": 255422.0}, "Borrowings, non-current portion": {"2018": 2307909.0, "2019": 2891973.0}, "Lease liabilities, current portion": {"2018": 6675.0, "2019": 9363.0}, "Lease liabilities, non-current portion": {"2018": 199424.0, "2019": 195567.0}, "Total debt": {"2018": 3034558.0, "2019": 3352325.0}, "Total equity": {"2018": 1983122.0, "2019": 1649853.0}, "Total debt and equity": {"2018": 5017680.0, "2019": 5002178.0}, "Gearing ratio": {"2018": 60.48, "2019": 67.01}}
gearing_ratio_2019 = df["Gearing ratio"]["2019"]
gearing_ratio_2018 = df["Gearing ratio"]["2018"]
answer = gearing_ratio_2019 - gearing_ratio_2018