Name the progressive Career and Single-Season leaders for each NFL stat. Players are listed once for each interval in which they were the leader, so if they had two non-consecutive intervals for one stat they will be listed twice for that one. Year span as well as that stat for first and last year shown. For example, the active interceptions leader from 1948-50 was the leader with 31 in 1948 and led with 34 in 1950.