Year % 1982 77.00355 1983 78.94439 1984 77.9608 1985 77.99588 1986 78.76675 1987 78.87825 1989 80.11457 1990 80.73768 1991 80.22547 1992 80.80636 1993 81.12076 1994 81.94718 1995 82.47025 1996 82.76321 1998 84.54516 2000 85.56508 2001 84.58752 2003 87.93718 2004 89.25876 2005 89.54028 2006 89.51271 2007 90.20213 2008 89.73817 2009 90.73863 2011 90.97999 2016 90.93202 2017 91.23591