What is the difference in the value realized on vesting between Mr. Trezise and Mr. Dev? 
{"Mr. Storey": {"Number of Shares Acquired on Vesting(1)": 1063929, "Value Realized on Vesting(2)": 13479617}, "Mr. Dev": {"Number of Shares Acquired on Vesting(1)": 55490, "Value Realized on Vesting(2)": 749737}, "Mr. Goff": {"Number of Shares Acquired on Vesting(1)": 114167, "Value Realized on Vesting(2)": 1338934}, "Mr. Trezise": {"Number of Shares Acquired on Vesting(1)": 71576, "Value Realized on Vesting(2)": 812600}, "Mr. Andrews": {"Number of Shares Acquired on Vesting(1)": 16678, "Value Realized on Vesting(2)": 221859}}
trezise_value = df["Mr. Trezise"]["Value Realized on Vesting(2)"]
dev_value = df["Mr. Dev"]["Value Realized on Vesting(2)"]
answer = trezise_value - dev_value