Year	%
1989	73.3562
1990	75.46725
1991	76.90676
1992	78.91659
1993	78.79863
1994	80.45762
1995	83.10304
1996	83.87021
1997	84.01559
1998	84.30271
1999	85.17196
2000	85.80706
2001	87.31338
2002	88.48683
2003	87.61542
2004	87.64966
2005	88.84745
2006	89.96205
2007	90.43779
2008	90.39655
2010	90.8282
2011	90.75397
2012	89.50773
2013	89.38325
2014	89.54011
2015	90.1251
2016	89.76407
2017	90.30148