What was the difference between the weighted average grant date fair value of PSUs, RSUs and restricted stock that are granted as compared to those that are vested?
{"Unvested PSUs, RSUs and restricted stock outstanding, December 31, 2018": {"Number of Shares": 1570.0, "Weighted Average Grant Date Fair Value": 18.52}, "PSUs, RSUs and restricted stock granted": {"Number of Shares": 897.0, "Weighted Average Grant Date Fair Value": 9.63}, "PSUs, RSUs and restricted stock vested": {"Number of Shares": -368.0, "Weighted Average Grant Date Fair Value": 17.23}, "PSUs, RSUs and restricted stock forfeited": {"Number of Shares": -208.0, "Weighted Average Grant Date Fair Value": 18.24}, "Unvested RSUs and restricted stock outstanding, December 31, 2019": {"Number of Shares": 1891.0, "Weighted Average Grant Date Fair Value": 14.58}}
vested_weighted_avg_grant_date_fair_value = df["PSUs, RSUs and restricted stock vested"]["Weighted Average Grant Date Fair Value"]
granted_weighted_avg_grant_date_fair_value = df["PSUs, RSUs and restricted stock granted"]["Weighted Average Grant Date Fair Value"]
answer = vested_weighted_avg_grant_date_fair_value - granted_weighted_avg_grant_date_fair_value