Dallas Cowboys : biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 2015 -> 2016     0.563   (0.250 -> 0.813)
Decline:     2014 -> 2015    -0.500   (0.750 -> 0.250)
Last Year:   2024 -> 2025     0.029   (0.412 -> 0.441)