Activity Codes Sorting

I have some activity codes with hundreds of values. When I add a new value, instead of keeping it in the right alphanumeric sort, it puts it at the bottom of the list, so as an example, say a T10 code that I added after T09, and before T11, ends up at the bottom after the Zxx values.

I did enter it after T09, so why does it drop at the bottom? and since I have hundreds of values, I can't simply move it to the right spot. That is one value at a time and a royal waste of time.