Year	Percent
1993	98
2001	99.9
2002	99.5
2003	99.5
2004	99.9
2005	99.7
2006	98.8
2007	99.8
2008	99.9
2009	99.8
2010	99.8
2011	99.8
2012	99.5
2013	99.9
2014	99.9
2015	99.8
2016	99.8