Year	Percent
1991	51.257
1992	50.958
1993	56.296
1994	59.355
1995	59.507
1996	57.998
1997	56.221
1998	52.925
1999	52.238
2000	51.94
2001	50.071
2002	45.565
2003	43.736
2004	46.022
2005	48.737
2006	48.758
2007	50.088
2008	51.056
2009	46.439
2010	46.821
2011	46.55
2012	44.726
2013	45.892
2014	45.73
2015	45.741
2016	45.144
2017	45.727
2018	45.926
2019	45.772
2020	45.568
2021	45.325
2022	45.053