Year	Percent
1990	58.54
1991	58.31
1992	57.44
1993	58.15
1994	58.54
1995	59.49
1996	57.54
1997	59.72
1998	61.24
1999	60.82
2000	59.51
2001	61.74
2002	61.37
2003	61.41
2004	60.28
2005	62.45
2006	62.11
2007	62.95
2008	62.62
2009	62.03
2010	60.84
2011	60.18
2012	63.87
2013	63.39
2014	63.06
2015	61.95
2016	59.37
2017	60.2
2018	62.18
2019	64.47
2020	60.62