Year	%
1984	92.81826
1985	93.55325
1986	93.26441
1987	93.00011
1988	92.51794
1989	92.67406
1990	93.11521
1991	93.53024
1992	93.77967
1993	94.40169
1994	94.56083
1995	94.94502
1996	95.2615
1997	95.42627
1998	95.90705
1999	96.30705
2000	96.89406
2001	97.35477
2002	97.63757
2003	97.94469
2004	98.01262
2005	97.98103
2006	98.01334
2007	97.87692
2008	97.87178
2009	97.92995
2010	98.04781
2011	98.18604
2012	97.53851
2013	97.93107
2014	98.23343
2015	98.02903
2016	98.1548
2017	98.1457