Is it possible to sort UOM entries manually?

Is it possible to sort UOM entries manually?
 
Unfortunately, it is not possible to sort UOM entries manually, however, a possible work around is to add spaces by editing the entries. For example, if you are creating a pricing engine for shirts. XS, S, M, L, XL and  you want 'xs' to be appeared at the top of the list, give 5 to 6 character length space before the name 'xs'. For the remaining entries, reduce the space by one.