Year Index 1980 28.06 1981 28.899 1982 31.294 1983 33.587 1984 39.181 1985 39.662 1986 39.047 1987 37.465 1988 37.101 1989 36.942 1990 35.27 1991 35.504 1992 35.497 1993 37.677 1994 55.506 1995 62.543 1996 65.413 1997 68.17 1998 70.651 1999 71.206 2000 72.805 2001 78.19 2002 83.404 2003 87.408 2004 84.881 2005 85.986 2006 87.485 2007 90.051 2008 97.708 2009 100 2010 105.386 2011 108.861 2012 110.877 2013 114.589 2014 119.068 2015 122.767 2016 121.455 2017 119.339 2018 119.835 2019 121.133 2020 123.259 2021 125.251 2022 127.261 2023 129.233 2024 131.33