Year	Percent
1991	48.62
1992	48.3
1993	49.272
1994	46.769
1995	46.753
1996	46.827
1997	46.375
1998	45.911
1999	46.468
2000	48.414
2001	48.315
2002	46.068
2003	49.401
2004	47.998
2005	47.327
2006	36.888
2007	43.477
2008	48.641
2009	51.224
2010	51.752
2011	53.431
2012	52.643
2013	51.109
2014	50.138
2015	49.346
2016	49.392
2017	49.106
2018	49.043
2019	48.936
2020	48.801
2021	48.651
2022	48.5