Split and calculate only the latest rate

Hi expert,

I face a problem that i would like to calucate only the latest rate of a wage type. However, the wage type may be split due to whatever reason.

E.g.

9ZZZ Rate01 100

9ZZZ Rate02 200

The above split may be happend due to postion change or wage increase. However, I have a rule that only want to calcualte the latest rate (i.e. in this case, I only want Rate02 which is 200). Any insight?