Year	Percent
1990	71.47
1991	71.47
1992	71.66
1993	72.21
1994	72.69
1995	72.6
1996	72.46
1997	72.23
1998	72.03
1999	72.41
2000	71.12
2001	70.1
2002	69.94
2003	72.38
2004	69.43
2005	68.61
2006	67.52
2007	67.93
2008	68.43
2009	69.63
2010	70.33
2011	71.51
2012	71.99
2013	72.55
2014	73.75
2015	74.09
2016	75.55
2017	76.1
2018	77.55
2019	78.24