What was the percentage change in Thereof defined-contribution in 2019 from 2018?
{"Short-term employee benefits": {"2019": 17378, "2018": 18652, "2017": 16634}, "Share-based payment1)": {"2019": 32393, "2018": 23646, "2017": 25723}, "Subtotal1)": {"2019": 49771, "2018": 42298, "2017": 42357}, "Post-employment benefits": {"2019": 2825, "2018": 1106, "2017": 1312}, "Thereof defined-benefit": {"2019": 2056, "2018": 250, "2017": 423}, "Thereof defined-contribution": {"2019": 769, "2018": 856, "2017": 889}, "Total1)": {"2019": 52596, "2018": 43404, "2017": 43669}}
defined_contribution_2019 = df["Thereof defined-contribution"]["2019"]
defined_contribution_2018 = df["Thereof defined-contribution"]["2018"]
answer = (defined_contribution_2019 - defined_contribution_2018) / defined_contribution_2018 * 100.0