What is the percentage increase in total number of shares purchased between December 2018 and January 2019?
{"December 1 - December 31, 2018": {"Total Number of Shares Purchased": 75000.0, "Average Price Paid per Share (1)": 12.96, "Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs": 75000.0, "Approximate Dollar Value of Shares that may be Purchased Under the Plans or Programs (2)": 19028173.0}, "January 1 - January 31, 2019": {"Total Number of Shares Purchased": 524577.0, "Average Price Paid per Share (1)": 14.0, "Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs": 524577.0, "Approximate Dollar Value of Shares that may be Purchased Under the Plans or Programs (2)": 11685543.0}, "February 1 - February 28, 2019": {"Total Number of Shares Purchased": 116042.0, "Average Price Paid per Share (1)": 14.53, "Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs": 116042.0, "Approximate Dollar Value of Shares that may be Purchased Under the Plans or Programs (2)": 10000013.0}, "Total": {"Total Number of Shares Purchased": 715619.0, "Average Price Paid per Share (1)": 13.97, "Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs": 715619.0, "Approximate Dollar Value of Shares that may be Purchased Under the Plans or Programs (2)": 10000013.0}}
total_shares_2019 = df["January 1 - January 31, 2019"]["Total Number of Shares Purchased"]
total_shares_2018 = df["December 1 - December 31, 2018"]["Total Number of Shares Purchased"]
answer = ( ( total_shares_2019 - total_shares_2018 ) / total_shares_2018 ) * 100.0