Year	%
1986	77.80459
1987	78.79278
1988	76.99773
1989	78.07333
1990	80.74844
1991	82.63695
1992	85.1675
1993	85.04615
1994	86.84623
1995	89.97362
1996	90.63255
1997	90.44057
1998	90.27351
1999	91.14758
2000	91.10021
2001	92.5193
2002	91.60853
2003	92.80228
2004	92.80326
2005	93.84431
2006	94.82683
2007	94.56138
2008	94.85054
2009	94.44707
2010	94.26596
2011	94.7372
2012	93.93847
2013	93.35701
2014	93.95951
2015	94.36987
2016	94.54036
2017	95.20228