Year Index 1980 5.536 1981 6.28 1982 6.932 1983 7.916 1984 8.408 1985 8.755 1986 10.143 1987 11.491 1988 12.758 1989 13.788 1990 15.019 1991 16.212 1992 19.626 1993 21.367 1994 23.28 1995 25.067 1996 26.867 1997 29.043 1998 31.461 1999 35.041 2000 36.23 2001 37.112 2002 38.187 2003 39.998 2004 41.583 2005 43.471 2006 46.932 2007 49.843 2008 53.171 2009 59.883 2010 65.612 2011 71.888 2012 77.859 2013 85.546 2014 93.278 2015 100.006 2016 109.938 2017 114.835 2018 119.601 2019 125.459 2020 133.614 2021 141.898 2022 149.986 2023 158.235 2024 166.621