Here is what you need to be familiar with to understand the Orders Per Customer report:
1.) Orders, greater than, 0 (FILTER): This filter ensures that only customers who have placed an order at your store count towards the total. It's best to leave this alone.
2.) Orders: The number of Orders placed by this group of customers.
For example, each customer added within that timeframe will be bucketed into rows for 1, 2, 3 (etc) orders, depending on how many they've placed at your store.
3.) Customers: The number of customers for each of those rows.
For example, 366 customers created in the last two years have placed 2 orders at the store.
4.) Customers (% Total): The percentage of the total number of customers that this row represents.
For example, 366 customers is 14.62% of the 2,504 total.