What percentage of national football league players retire?

Approximately 2.5% of all players will get a Super Bowl ring. Each year, only 1 team of 32 (3.1%) wins the Super Bowl. There are occassionally repeat champions such that, on average, 7 teams win every 10 years plus there is, on average, 23% turnover each year. Using pragmatic regression analysis, this calcuates to 2.51236% of all players win a ring.