Year	Percent
1990	50.69
1991	50.6
1992	50.54
1993	50
1994	50.34
1995	49.22
1996	49.79
1997	50.42
1998	50.38
1999	50.67
2000	51.07
2001	50.88
2002	50.8
2003	51.25
2004	51.72
2005	51.3
2006	50.85
2007	50.81
2008	50.77
2009	51.2
2010	51.55
2011	51.53
2012	51.87
2013	52.21
2014	52.07
2015	53.03
2016	52.83
2017	52.63
2018	52.44
2019	52.51
2020	50.24