The difference between the 1st and 2nd digits is divided into 5 portions

The difference between the 1st and 2nd digit of the lottery numbers is divided into 5 parts.

Part 1: 1 - 7

Part 2: 8 - 13

Part 3: 14 - 19

Part 4: 20 - 25

Part 5: 26 - 31