What is the value of the 2019 time charter revenues as a percentage of the 2018 time charter revenues?
{"Spot charter revenues*": {"2019": 283007, "2018": 259978, "2017": 257495}, "Time charter revenues  ": {"2019": 34213, "2018": 29038, "2017": 39646}, "Total Voyage Revenues  ": {"2019": 317220, "2018": 289016, "2017": 297141}}
time_charter_revenues_2019 = df["Time charter revenues  "]["2019"]
time_charter_revenues_2018 = df["Time charter revenues  "]["2018"]
answer = time_charter_revenues_2019 / time_charter_revenues_2018 * 100.0