Year	Percent
1991	53.67
1992	53.44
1993	53.3
1994	53.26
1995	53.14
1996	53.06
1997	53.03
1998	53
1999	52.95
2000	52.99
2001	53
2002	52.91
2003	50.52
2004	54.66
2005	53.4
2006	53.18
2007	52.82
2008	54.33
2009	55.91
2010	52.48
2011	51.52
2012	54.15
2013	53.61
2014	50.85
2015	49.08
2016	51.69
2017	50.52
2018	51.48
2019	50.76