Summing and grouping within a Http web service

I have a created a Http web service workflow that scans through a list and with a loop returns 2 columns.

Empires (Employee name)
daystaken (Days)

The results from the current workflow are below. Is it possible to get a process that sums up the days per employee (note there may be more than one row as shown in the current results)? Please note I want to achieve one line per employee with the total of the days.