After a short week, the Lions hosted their division rivals the Chicago Bears for their 75th annual Thanksgiving Day Game. Detroit spotted Chicago a 14-3 first quarter lead, as Jay Cutler hit Alshon Jeffery with touchdown passes of 10 and 6 yards, wrapped around a Matt Prater 46-yard field goal.  In the second quarter, Calvin Johnson ended his team's nine-quarter touchdown drought by catching a 25-yard TD pass from Matthew Stafford. Before the half ended, Joique Bell scored on a 1-yard run and Stafford again hooked up with Johnson, this time on a 6-yard TD, putting Detroit up 24-14. Robbie Gould closed the gap to seven points with a 35-yard field goal in the third quarter.  Detroit scored the game's final 10 points in the fourth quarter. Joique Bell capped a 95-yard drive with his second 1-yard TD run and Matt Prater hit a 40-yard field goal, making the final score 34-17. The Lions tallied a season-high 474 yards of offense on the day.
Question: How many yards fewer was Prater's last field goal compared to his first?
Answer: 6