I have data that looks like this (three columns: Date, IGN and AP):
I would like to create a new column AGE that when looking up the last value for the IGN column (just showing Emxmari0 in this case) I would like to look up the AP (3590) for last row of the given IGN (the 8/31/2019 date) and then look backwards in time to find the row for the given IGN with a different value in the AP column (the 8/12/2019 date vas a value of 3580), then with the two rows identified give the difference in days using the A column, 19 in this case. If a row for a given IGN isn’t the last row (which presumes the highest date) then the value for AGE would be blank.
Any help toward figuring this out would be appreciated!
By: Joel Breazeale