Additional documents - Indiana

This is my 1st year filing as self employed and Indiana just requested more documentation. They want proof of my three largest incomes and I don't know exactly what that means. I sell homemade arts and crafts solely by word of mouth and occasionally at my kids sporting events. There are no large orders or sales to speak of and all my transactions are in cash. I have copies of receipts but none of the sales would be considered "large". So what should I send them?