Year	%
1985	79.70671
1986	80.10338
1987	82.87674
1988	74.73043
1989	75.50073
1990	76.56407
1991	77.77803
1992	78.99846
1993	80.21269
1994	81.47135
1995	82.71157
1996	83.93976
1997	85.1275
1998	86.29467
1999	87.49351
2000	86.87778
2001	89.25374
2002	91.28437
2003	85.41895
2004	86.19562
2005	87.41181
2006	88.25425
2007	88.49238
2008	89.3026
2009	90.29702
2010	90.75379
2011	90.97846
2012	90.19353
2013	90.29015
2014	89.59067
2015	90.72861
2016	89.68054
2017	91.43389