Los Angeles Dodgers : biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 1944 -> 1945      15.6   (40.9  ->  56.5)
Decline:     1991 -> 1992     -18.5   (57.4  ->  38.9)
Last Year:   2017 -> 2018      -7.8   (64.2  ->  56.4)