Cross table, using If statement adding extra column at end, want to remove.

I have a cross table, at the first row is the header of years, it is using a If statement: =If(Month([ABCDEFGH])="December";FormatNumber(Year([ABCDEFGH]);"####")). It is always insert a column at the very end with no value. I'm thinking in the If statement if the condition is not met(false) then it shouldn't display anything? which is what I want If the condition is not met(false) then don't show a column. Can someone please help? Thanks.