Year	Percent
1992	0.98364
1993	0.97016
1994	0.97358
1995	0.97437
1996	0.97604
1997	0.97859
1998	0.97808
1999	0.98091
2000	0.98453
2001	0.98538
2002	0.98428
2003	0.98222
2004	0.98259
2005	0.98251
2006	0.98018
2007	0.98219
2008	0.98018
2009	0.96248
2010	0.96348
2011	0.96235
2012	0.96336
2013	0.96588
2014	0.96575
2015	0.96513