Los Angeles Lakers biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 2019 -> 2020     0.281   (0.451 -> 0.732)
Decline:     2004 -> 2005    -0.268   (0.683 -> 0.415)
Last Year:   2025 -> 2026     0.036   (0.610 -> 0.646)