Year Index 1980 49.19 1981 54.847 1982 60.332 1983 65.038 1984 72.647 1985 68.361 1986 65.49 1987 66.603 1988 63.073 1989 63.956 1990 62.933 1991 59.723 1992 60.38 1993 60.295 1994 80.017 1995 86.53 1996 90.335 1997 94.442 1998 96.768 1999 96.724 2000 100 2001 103.729 2002 106.626 2003 106.157 2004 106.771 2005 114.346 2006 115.97 2007 121.026 2008 130.09 2009 137.996 2010 141.534 2011 147.861 2012 154.922 2013 157.304 2014 157.137 2015 158.735 2016 159.116 2017 158.939 2018 163.786 2019 167.405 2020 170.759 2021 174.336 2022 176.74 2023 180.211 2024 183.755