Metrix Box In Report

HI All,

Is there anyway to add Percentage after Subtotal Column and subtotal Line.
Example :- I need to Get Last Column and Last Line.
Sp1 SP2 SP3 Total Percentage%
CustGrop 1 500 100 200 800 61.54%
CustGrop 2 150 200 150 500 38.46%
Total 650 300 350 1300 100 %
Percentage% 50 % 23.08% 26.92%100%

Please advice.
Sameera