There should be a 4-digit number somewhere on the inside of the sides of the heel. The final digit is the last number. On my black Park Avenues, it's 5615, so the 5 last. On my brandy Westgates, it's 6648, so the 8 last. Etc.
Here is a more or less complete list of current and some former AE styles and the lasts they were made on.