Year	Percent
1986	71.1
1990	80.6
1995	83.6
1998	91.3
1999	92.1
2000	86.1
2001	93.1
2002	94.5
2003	95
2004	95.6
2005	90.7
2006	97.1
2007	97.8
2008	98.1
2009	98.6
2010	94.8
2011	99.2
2012	98.7
2013	98.7
2014	98.9
2015	95.9
2016	99.2