What is the percentage change in the number of restricted stock units originally issued in October 2015 and 2016?
{"Date of award:": {"Restricted Stock Units(1)": 2015, "Restricted Stock Units(2)": 2016, "Restricted Stock Units(3)": 2017, "Restricted Stock Units(4)": 2018}, "Original number of awards issued:": {"Restricted Stock Units(1)": 13250, "Restricted Stock Units(2)": 13000, "Restricted Stock Units(3)": 13000, "Restricted Stock Units(4)": 15050}, "Service period:": {"Restricted Stock Units(1)": 36, "Restricted Stock Units(2)": 36, "Restricted Stock Units(3)": 36, "Restricted Stock Units(4)": 36}, "Estimated fair value of award at grant date:": {"Restricted Stock Units(1)": 1112000, "Restricted Stock Units(2)": 1191000, "Restricted Stock Units(3)": 1177000, "Restricted Stock Units(4)": 1264000}, "Non-vested awards outstanding at -- September 30, 2019:": {"Restricted Stock Units(1)": 100, "Restricted Stock Units(2)": 4334, "Restricted Stock Units(3)": 8667, "Restricted Stock Units(4)": 15050}, "Fair value of non-vested awards at -- September 30, 2019 of approximately:": {"Restricted Stock Units(1)": 8000, "Restricted Stock Units(2)": 330000, "Restricted Stock Units(3)": 661000, "Restricted Stock Units(4)": 1148000}}
restricted_stock_units_2016 = df["Original number of awards issued:"]["Restricted Stock Units(2)"]
restricted_stock_units_2015 = df["Original number of awards issued:"]["Restricted Stock Units(1)"]
answer = (restricted_stock_units_2016 - restricted_stock_units_2015) / restricted_stock_units_2015 * 100.0