Year	Percent
1990	63.04
1991	63.2
1992	63.4
1993	64.4
1994	65.3
1995	64.54
1996	63.05
1997	62.86
1998	64.92
1999	64.7
2000	64.18
2001	63.66
2002	63.12
2003	64.78
2004	63.38
2005	63.93
2006	64.48
2007	65.08
2008	65
2009	64.89
2010	63.37
2011	63.15
2012	63.79
2013	64.35
2014	63.12
2015	62.31
2016	63.19
2017	63.08
2018	62.85
2019	63.15