From 1973 to 1977, there were, on average, 7.8 players, with 1,000 yards rushing each year.
From 2016 to 2020, there were, on average, 11 players, with 1,000 yards rushing each year.
I thought the NFL was becoming more of a passing league. What gives?
Well, in 1978, the NFL moved from a 14 game schedule to a 16 game schedule. More games mean more stats.
Now that the NFL has thrown their beautiful league balance away in favor of the extra revenue that comes from one more game, we can expect single season records to come under assault.