Year	Percent
1990	46.63
1991	46.7
1992	46.67
1993	46.69
1994	47.65
1995	46.48
1996	45.96
1997	45.42
1998	44.86
1999	46.35
2000	46.12
2001	45.62
2002	45.13
2003	45.63
2004	46.13
2005	46.62
2006	47.05
2007	48.13
2008	48
2009	48.64
2010	49.11
2011	48.81
2012	49.15
2013	49.61
2014	49.59
2015	47.92
2016	47.7
2017	46.39
2018	44.93
2019	44.83
2020	43