What was the difference between the vested and granted Weighted-Average Grant-Date Fair Value?
{"": {"Number of Shares": "", "Weighted-Average Grant-Date Fair Value": "(per share)"}, "Outstanding at April 1, 2018": {"Number of Shares": 243354.0, "Weighted-Average Grant-Date Fair Value": 10.78}, "Granted": {"Number of Shares": 265452.0, "Weighted-Average Grant-Date Fair Value": 14.66}, "Vested": {"Number of Shares": -197917.0, "Weighted-Average Grant-Date Fair Value": 12.74}, "Forfeited": {"Number of Shares": -73743.0, "Weighted-Average Grant-Date Fair Value": 11.3}, "Outstanding at March 31, 2019": {"Number of Shares": 237146.0, "Weighted-Average Grant-Date Fair Value": 13.46}}
granted_fair_value = df["Granted"]["Weighted-Average Grant-Date Fair Value"]
vested_fair_value = df["Vested"]["Weighted-Average Grant-Date Fair Value"]
answer = granted_fair_value - vested_fair_value