What was the percentage change in employee costs from 2017 to 2018?
{"Employee costs*": {"2017": 18789, "2018": 20980, "2019": 24863}, "Share-based compensation (Note 22)": {"2017": 4565, "2018": 5216, "2019": 5107}, "Other expenses": {"2017": 16496, "2018": 15797, "2019": 17415}, "Total": {"2017": 39850, "2018": 41993, "2019": 47385}}
employee_costs_2018 = df["Employee costs*"]["2018"]
employee_costs_2017 = df["Employee costs*"]["2017"]
answer = ( employee_costs_2018 - employee_costs_2017 ) / employee_costs_2017 * 100.0