Year Percent 1970 95.86288 1971 96.16279 1972 96.56751 1973 96.95946 1974 97.33925 1975 97.70742 1976 98.06452 1977 98.30508 1978 98.64301 1979 98.97119 1980 99.28934 1981 99.5996 1982 99.90119 1983 100.29268 1984 100.57803 1985 100.76118 1986 101.03383 1987 101.30112 1988 101.65441 1989 101.90909 1990 102.06835 1991 102.31317 1992 102.55507 1993 102.79232 1994 102.93863 1995 103.16781 1996 103.30789 1997 103.53238 1998 103.66667 1999 103.79851 2000 104.00982 2001 104.13625 2002 104.26045 2003 104.38247 2004 104.50237 2005 104.6202 2006 104.73602 2007 104.84615 2008 104.95805 2009 104.98866 2010 105.09745 2011 105.1263 2012 105.23213 2013 105.33626 2014 105.36232 2015 105.4637