What was the percentage change in Diluted weighted average shares outstanding between 2018 and 2019?
{"Weighted average shares outstanding: -- Basic weighted average shares outstanding": {"2019": 116175, "2018": 116057, "2017": 118059}, "Add: Dilutive effect of stock options, RSUs, and contingently issuable -- shares": {"2019": 2396, "2018": 1575, "2017": 1385}, "Add: Dilutive effect of stock options, RSUs, and contingently issuable -- Diluted weighted average shares outstanding": {"2019": 118571, "2018": 117632, "2017": 119444}}
dwa_2019 = df["Add: Dilutive effect of stock options, RSUs, and contingently issuable -- Diluted weighted average shares outstanding"]["2019"]
dwa_2018 = df["Add: Dilutive effect of stock options, RSUs, and contingently issuable -- Diluted weighted average shares outstanding"]["2018"]
answer = (dwa_2019 - dwa_2018) / dwa_2018 * 100.0