New England Patriots : biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 1975 -> 1976     0.572   (0.214 -> 0.786)
Decline:     1980 -> 1981    -0.500   (0.625 -> 0.125)
Last Year:   2022 -> 2023    -0.236   (0.471 -> 0.235)