Year	Percent
1991	38.407
1992	39.075
1993	38.814
1994	38.254
1995	39.163
1996	39.97
1997	40.796
1998	40.111
1999	39.504
2000	40.28
2001	40.254
2002	38.722
2003	41.622
2004	41.483
2005	41.432
2006	40.56
2007	42.931
2008	44.347
2009	45.119
2010	44.185
2011	47.177
2012	48.576
2013	48.695
2014	48.483
2015	50.242
2016	47.999
2017	47.93
2018	48.101
2019	48.402
2020	48.691
2021	48.941
2022	49.198