What is the percentage change in total stock based compensation cost between 2018 and 2019?
{"Stock-based compensation cost: -- Common stock warrants": {"2019": "$\u2014", "2018": 512, "2017": 484}, "Stock-based compensation cost: -- Stock options": {"2019": 16489, "2018": 13279, "2017": 11295}, "Stock-based compensation cost: -- Restricted stock units": {"2019": 14585, "2018": 90, "2017": "\u2014"}, "Stock-based compensation cost: -- Employee stock purchase plan": {"2019": 3326, "2018": 2069, "2017": "\u2014"}, "Stock-based compensation cost: -- Total stock-based compensation cost": {"2019": 34400, "2018": 15950, "2017": 11779}}
total_stockbased_compensation_cost_2019 = df["Stock-based compensation cost: -- Total stock-based compensation cost"]["2019"]
total_stockbased_compensation_cost_2018 = df["Stock-based compensation cost: -- Total stock-based compensation cost"]["2018"]
answer = (total_stockbased_compensation_cost_2019 - total_stockbased_compensation_cost_2018) / total_stockbased_compensation_cost_2018 * 100.0