Year	%
1988	69.29827
1989	69.63228
1990	73.59564
1991	75.35753
1992	78.89155
1993	78.23585
1994	81.14241
1995	86.61887
1996	86.9069
1997	85.98425
1998	84.95178
1999	86.22784
2000	87.49695
2001	89.00316
2002	90.38236
2003	91.63286
2004	91.56776
2005	94.14359
2006	96.3545
2007	96.40183
2008	96.52214
2009	96.18212
2010	96.11417
2011	96.76877
2012	95.34668
2013	94.15813
2014	96.16007
2015	96.5986
2016	96.6193
2017	96.65002