Phoenix Mercury biggest year-to-year improvement/decline
based on regular season win percentage:

                            Change in 
                              win %
Improvement: 2003 -> 2004     0.265   (0.235 -> 0.500)
Decline:     2000 -> 2001    -0.219   (0.625 -> 0.406)
Last Year:   2006 -> 2007     0.147   (0.529 -> 0.676)