What is the percentage change in the net cash provided by operating activities between 2017 and 2018?
{"": {"2019": "", "2018": "(in thousands)", "2017": ""}, "Net cash provided by (used in) operating activities": {"2019": -9885, "2018": 25601, "2017": 16586}, "Net cash used in investing activities": {"2019": -3822, "2018": -13203, "2017": -1873}, "Net cash provided by (used in) financing activities": {"2019": "$\u2014", "2018": -21556, "2017": 12778}}
net_cash_2018 = df["Net cash provided by (used in) operating activities"]["2018"]
net_cash_2017 = df["Net cash provided by (used in) operating activities"]["2017"]
answer = ( net_cash_2018 - net_cash_2017 ) / net_cash_2017 * 100.0