Indianapolis Colts : biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 1998 -> 1999     0.625   (0.188 -> 0.813)
Decline:     2010 -> 2011    -0.500   (0.625 -> 0.125)
Last Year:   2024 -> 2025     0.000   (0.471 -> 0.471)