How can I calculate a percentage of a YES/NO field in a Pivot Tab

I have a list of data and one of the fields is YES, Recommend Our Company or
NO, Don't Recommend Our Company. We are trying to calculate the percentage of
YES answers and use the result in a pivot table. The YES/NO answers are part
of a list of other customer survey questions that we are mapping in a pivot
table. In summary, I need to see % of YES answers by customer type in my
pivot table.

Any recommendations.