Percentage Of Total For Cells In A Range Equaling A Specific Numeric Value

I am trying to create a formula that shows a percentage of cells within a range that contain a particular number. This percentage is based on another cell, which is the total number of all audits. Each audit has rating columns, with a numeric value indicating it's rating. I need to count those cells within the range that equal the numeric value assigned to the rating, and then divide that total by the total number of audits to obtain a percentage of calls with each particular rating in each category.

Here is an example of what I'm trying to accomplish:

A1 = 2 (Total audits)
B1 = 07/31/2009 (Date of first audit)
C1 = 3 (Rating of first category)
D1 = 1 (Rating of second category)
E1 = 2 (Rating of third category)
F1 = 08/03/2009 (Date of second audit)
G1 = 0 (Rating of first category)
H1 = 2 (Rating of second category)
I1 = 2 (Rating of third category)

The percentage of audits within the first category that have a rating of 3 would be 50%.
The percentage of audits within the second category that have a rating of 3 would be 0%.
The percentage of audits within the third category that have a rating of 2 would be 100%.