doubt with hash

[Anish Kumar K.]

Hi All

I have a hash say. %browserType in which assume there are values...

%browserType=(
"IE"=>2,
"NETSCAPE"=>3,
"FIREFOX"=>5
);

I need to calculate one morething say percentage utilisation for each browser..

ie..If IE is 2 = the percentage is calculated as (2/(2+3+5))*100
       NETSCAPE=(3/(2+3+5))*100
       FIREFOX=(5/(2+3+5))*100

and pass this in this single hash...I am new to this hash...I thought there are 
two values possible, KEY and VALUE in hash
is there a way I can add one more 

"IE"=>2=>10
"NETSCAPE=>3=>20

Please help

Anish