Percentage of . . .

[chaserwill]

Looking at purchasing card data for my employer. A red flag for potential abuse of the program is a cardholder using a specific vendor a high percentage of time.



For example, let's say one month of p card data has 2,000 separate transactions (cardholder name, vendor name, amount, post date, etc.). John Doe accounts for 100 of these transactions and of these 100, he's used ABC Co. 95 times.

What would be the most efficient and effective formula/logic that can be applied to the entire spreadsheet that would "red flag" this cardholder as a "specific vendor - high percentage" user so his activity can be further examined?