Average between Years

[excelgrrl]

I currently have a student's name in column A, Enrollment date in B (in the form of dd/mm/yy) and the current school year in C (in the form of yyyy).

I need to get the average years each student has attended this school. I have tried to copy column B and past only the values so I could then pull only the last 4 digits, however; the date of 09/10/07 pastes as 39335. I have tried everything I can think of and I can't figure this out.

I have searched the boards and can't find what I need to solve this.

[mewingkitty]

39335
is 07, in years, if the cell is formatted custom "yy" to display years.
or "yyyy" to display 2007.