Ah, rule changes. Here are some from each year with a few added teams that appear to be affected most. Keep in mind roster/coaching changes and other x-factors may also be the case.
(I was bored!)
1972: hash marks moved in to boost offense. (defenses now could not use sideline as extra defender)
Highest points scored adjustment from 1971: Dolphins, Redskins, Steelers
Super Bowl: Dolphins 14, Redskins 7
1974: Goalposts moved to back of end zone. (to open up end zone pass patterns)
Biggest jump in passing TDs from 1973: Vikings, Raiders, Cardinals
Super Bowl: Steelers 16, Vikings 6
1976: Facemask penalties enforced (5 for incidental, 15 for twisting/pulling)
Most defensive penalties (facemasks unavailable): Bucs, Oilers, Seahawks
Most 1st downs allowed by penalty: Broncos, Saints, Raiders
Super Bowl: Raiders 32, Vikings 14
1977: Headslap is outlawed. (Deacon used it a lot, Youngblood was his protégé)
Biggest decline in sacks from 1976: 49ers (-19), Oilers (-18), Vikings (-15)
Rams: 45 in 1976, 36 in 1977
Youngblood: 12.5 in 1976, 7 in 1977
Super Bowl: Cowboys 27, Broncos 10
1978: Outlawed contact with receivers beyond 5 yards, OL can extend arms blocking
League totals before/after: 1977: 388 TD passes/1978: 468 TD passes
Biggest jump passing yards/TDs: Chargers (both; before Coryell), Saints (yards), Steelers (TDs)
Super Bowl: Steelers 35, Cowboys 31
1981: chop block eliminated from pass plays (9ers were notorious for this even after changes)
Biggest drop in passing yards/TDs from 1980: Saints, Rams (minus Ferragamo), Eagles (yards)
Super Bowl: 49ers 26, Bengals 21
1981: Stickum is outlawed (Lester Hayes Rule), Biletnikoff retired in 1978
Biggest drop in catches from 1980: Jefferson (-43), Earl Cooper (-32), William Andrews (-30)
Biggest drop in interceptions: Hayes (-10), he had 13 in 1980
1984: Unsportsmanlike Conduct penalty for prolonged celebration (Gastineau & Fun Bunch rule)
Most celebration penalties: data unavailable
Super Bowl: Raiders 39, Redskins 6
1985: Quarterback kneeldown (victory formation) enforced
Largest margin of QB rushing yardage from 1984: Dickey (-18), Marino (-17)
Super Bowl: Bears 46, Patriots 10
1993: spike added to stop the game clock
Most clock-stopping spikes: data unavailable
First fake spike for TD: Dan Marino (1994)
Super Bowl: Cowboys 30, Bills 13
1994: 2 point conversion added
Most 2-point conversions made: Dolphins 6, Browns-Oilers-Seahawks-Vikings 4
Super Bowl: 49ers 49, Chargers 26
1999: Instant Replay with challenge flags
Most Instant Replay challenges: data unavailable
Super Bowl: Rams 24, Titans 17
1999: Tuck Rule
Teams who benefited most: Jets 2001 (vs Patriots), Patriots 2001 (2002 playoffs vs Raiders)
Rams: Kurt Warner got the benefit of the tuck rule twice in 2001 reg season.
2001: Taunting and Roughing the Passer fouls strictly enforced
Roughing the passer penalties: 2000 - 75, 2001 - 77
Taunting penalties: 14
Super Bowl: *Patriots 20-17
2005: Outlawed the Horse Collar tackle (Roy Williams Rule)
Horse Collar Tackle penalties: data unavailable
Super Bowl: Steelers 21, Seahawks 10
2006: Defenders prohibited from hitting passer in the knee
Hitting passer in the knee penalties: data unavailable
Super Bowl: Colts 29, Bears 17
2010: Overtime extended for playoffs
First New Overtime playoff game: 2012 playoffs - Broncos 29, Steelers 23
Super Bowl: Packers 31, Steelers 25
2011: Defenseless player rule enforced
Hitting defenseless player penalties: data unavailable
Super Bowl: Giants 21, Patriots 17
2012: Overtime extended for reg season
First New Overtime reg season game (when FG was the 1st score): Texans 43, Jag-wahs 37
Super Bowl: Ravens 34, 49ers 31
How the game has changed penalty-wise:
Off Holding: 1994 - 614, 2018 - 704
Roughing the Passer: 1994 - 58, 2018 - 114
Unnecessary Roughness: 1994 - 83, 2018 - 204
Taunting: 1994 - 3, 2018 - 24
Pass Interference: 1994 - 208, 2018 - Def 236, Off 83
False Start: 1994 - 454, 2018 - 566
Okay this turned into a project lol so I'm leaving out a lot of other stuff including additional & extended rule changes. Originally wanted to list these to signify changes that effect QB ratings, what teams may have benefited... and a lot of other factors involved. Game has changed a lot, we all know that much!