Year	Percent
1990	49.35
1991	49.42
1992	49.43
1993	49.47
1994	50.38
1995	49.03
1996	48.5
1997	47.94
1998	47.37
1999	49.01
2000	48.95
2001	48.58
2002	48.22
2003	48.7
2004	49.18
2005	49.63
2006	50.03
2007	51.06
2008	50.98
2009	51.57
2010	52
2011	51.8
2012	52.18
2013	52.78
2014	52.86
2015	51.07
2016	50.68
2017	49.36
2018	47.91
2019	47.87