Year	%
1985	78.70349
1986	78.91234
1987	80.33279
1988	76.3073
1989	77.15851
1990	77.64211
1991	78.98049
1992	79.80388
1993	80.43282
1994	81.31643
1995	82.10058
1996	82.83616
1997	83.45353
1998	84.21091
1999	84.89463
2000	84.24952
2001	86.50835
2002	84.49955
2003	86.29057
2004	85.61826
2005	86.91595
2006	88.3006
2007	87.55043
2008	88.04614
2009	87.78657
2010	87.35081
2011	88.67128
2012	87.7333
2013	87.58502
2014	87.39943
2015	88.48047
2016	88.12126
2017	88.97856