Year	Percent
1991	53.157
1992	53.121
1993	52.121
1994	56.019
1995	57.038
1996	56.056
1997	59.031
1998	57.941
1999	56.796
2000	56.303
2001	55.587
2002	56.417
2003	57.18
2004	57.929
2005	57.284
2006	57.75
2007	55.347
2008	56.7
2009	54.811
2010	56.254
2011	57.729
2012	53.098
2013	50.827
2014	58.775
2015	51.492
2016	51.91
2017	51.551
2018	51.28
2019	51.009
2020	50.738
2021	50.488
2022	50.241