What is the percentage change in total revenue between 2017 and 2018?
{"Subscription and returns -- Tax determination": {"2019": 203584, "2018": 147847, "2017": 114575}, "Subscription and returns -- Tax returns and compliance management": {"2019": 127815, "2018": 91239, "2017": 74454}, "Subscription and returns -- Interest income on funds held for customers": {"2019": 3213, "2018": 1055, "2017": "-"}, "Subscription and returns -- Total subscription and returns": {"2019": 334612, "2018": 240141, "2017": 189029}, "Subscription and returns -- Professional services": {"2019": 24399, "2018": 15126, "2017": 12476}, "Subscription and returns -- Total revenue (U.S.)": {"2019": 359011, "2018": 255267, "2017": 201505}, "Subscription and returns -- Total revenue (non U.S.)": {"2019": 23410, "2018": 16831, "2017": 11654}, "Subscription and returns -- Total revenue": {"2019": 382421, "2018": 272098, "2017": 213159}}
total_revenue_2018 = df["Subscription and returns -- Total revenue"]["2018"]
total_revenue_2017 = df["Subscription and returns -- Total revenue"]["2017"]
answer = (total_revenue_2018 - total_revenue_2017) / total_revenue_2017 * 100.0