What was the percentage change in Net cash provided by operating activities between 2018 and 2019?
{"Net cash provided by operating activities": {"2019": 1831, "2018": 1790, "Increase (Decrease)": 41}, "Net cash used in investing activities": {"2019": -22, "2018": -230, "Increase (Decrease)": 208}, "Net cash used in financing activities": {"2019": -237, "2018": -2020, "Increase (Decrease)": 1783}, "Effect of foreign exchange rate changes": {"2019": -3, "2018": -31, "Increase (Decrease)": 28}, "Net increase (decrease) in cash and cash equivalents and restricted cash": {"2019": 1569, "2018": -491, "Increase (Decrease)": 2060}}
net_cash_2019 = df["Net cash provided by operating activities"]["2019"]
net_cash_2018 = df["Net cash provided by operating activities"]["2018"]
answer = (net_cash_2019 - net_cash_2018) / net_cash_2018 * 100.0