Year	Percent
1991	30.038
1992	32.044
1993	33.672
1994	33.082
1995	32.553
1996	31.961
1997	32.825
1998	33.578
1999	32.641
2000	31.99
2001	32.017
2002	32.079
2003	33.025
2004	34.823
2005	34.593
2006	35.569
2007	37.88
2008	39.009
2009	38.749
2010	42.393
2011	44.603
2012	45.154
2013	46.01
2014	46.558
2015	46.53
2016	46.691
2017	46.806
2018	46.93
2019	47.03
2020	47.122
2021	47.211
2022	47.292