Year	Percent
1991	35.151
1992	35.15
1993	35.039
1994	35.078
1995	35.201
1996	35.228
1997	35.272
1998	35.254
1999	35.213
2000	35.039
2001	34.833
2002	34.503
2003	34.571
2004	34.546
2005	34.53
2006	34.5
2007	34.506
2008	34.514
2009	34.57
2010	34.539
2011	34.546
2012	34.508
2013	34.491
2014	34.458
2015	34.445
2016	34.419
2017	34.395
2018	34.33
2019	34.267
2020	34.204
2021	34.148
2022	34.098