Year	Percent
1990	47.79
1991	47.9
1992	48.01
1993	48.07
1994	48.08
1995	48.03
1996	47.96
1997	47.88
1998	47.8
1999	47.76
2000	47.75
2001	47.87
2002	48.02
2003	48.19
2004	48.35
2005	48.47
2006	48.33
2007	48.16
2008	47.99
2009	47.83
2010	47.7
2011	47.76
2012	47.86
2013	48.02
2014	48.19
2015	48.37
2016	48.52
2017	48.67
2018	48.78
2019	48.9
2020	47.06