Year	%
1983	77.08898
1984	76.37576
1985	76.67719
1986	76.88577
1987	78.28283
1988	74.6867
1989	75.50859
1990	76.07798
1991	77.3856
1992	78.2723
1993	79.05508
1994	79.99127
1995	80.82601
1996	81.68145
1997	82.42988
1998	83.2671
1999	84.02686
2000	83.68548
2001	85.98867
2002	85.60844
2003	85.30064
2004	84.84125
2005	86.44561
2006	87.80878
2007	87.49557
2008	87.95986
2009	88.1871
2010	88.15677
2011	88.9401
2012	87.85798
2013	87.93263
2014	87.71047
2015	88.76824
2016	88.30668
2017	89.22486