Year	Percent
1990	47.27
1991	47.33
1992	47.4
1993	47.48
1994	47.54
1995	47.54
1996	47.54
1997	47.51
1998	47.46
1999	47.4
2000	47.34
2001	47.33
2002	47.32
2003	47.32
2004	47.7
2005	47.08
2006	46.48
2007	45.8
2008	45.1
2009	45.03
2010	44.89
2011	44.71
2012	44.51
2013	44.29
2014	44.07
2015	43.83
2016	43.6
2017	42.84
2018	42.14
2019	41.47