Year	Percent
1991	54.664
1992	53.302
1993	51.502
1994	49.272
1995	47.749
1996	47.031
1997	46.445
1998	45.751
1999	45.223
2000	44.968
2001	44.801
2002	44.844
2003	45.067
2004	46.401
2005	47.176
2006	48.724
2007	48.546
2008	47.454
2009	46.595
2010	45.955
2011	45.777
2012	46.039
2013	46.82
2014	47.024
2015	46.933
2016	46.858
2017	46.853
2018	46.766
2019	46.697
2020	46.703
2021	46.788
2022	46.905