Year	Percent
1991	45.512
1992	46.286
1993	45.114
1994	46.36
1995	45.016
1996	44.802
1997	46.133
1998	45.628
1999	45.178
2000	45.917
2001	49.092
2002	50.392
2003	51.365
2004	50.906
2005	49.72
2006	51.15
2007	52.647
2008	53.201
2009	53.418
2010	53.909
2011	52.486
2012	49.997
2013	47.749
2014	49.129
2015	49.329
2016	50.337
2017	51.548
2018	51.771
2019	51.903
2020	51.961
2021	52.036
2022	52.032