% of total in table

[#1]

I am looking to have a table with 2 columns one with value of times and have used this in my expression = count ([Injury Area] which works fine in 2 column i am looking to show this value as a % to the total

like below

many thanks in anticipation

any ideas on what expression to use

Injury Area	Header 2	Header 3
Head	50	50%
Arm	30	30%
leg	10	10%
face	10	10%

[maxgro]

maybe

count ([Injury Area]) / count (Total [Injury Area])