Solve this: Puzzle… Here is a list showing the month and a number for each month

Solve this: Puzzle.😎☝🎆

Here is a list showing the month and a number for each month .
☝January 713
☝February 823
☝March 531
☝ April 542
☝May 351
☝June 462
☝July 471
☝ August 683

⚡Decode the logic and find the number for September = ?
🌞Challenge is O P E N for all GENIUS😇
Please support yöür answer by logic

Pls explain this