Year	Percent
1991	52.345
1992	52.921
1993	52.753
1994	52.575
1995	53.966
1996	52.095
1997	52.164
1998	51.9
1999	51.535
2000	49.469
2001	49.761
2002	48.999
2003	47.973
2004	46.689
2005	46.138
2006	44.946
2007	43.141
2008	43.127
2009	42.344
2010	42.002
2011	42.35
2012	47.1
2013	47.319
2014	46.822
2015	46.321
2016	45.933
2017	46.338
2018	46.185
2019	46.053
2020	45.943
2021	45.79
2022	45.638