Year Index 1980 0.132 1981 0.144 1982 0.162 1983 0.192 1984 0.215 1985 0.239 1986 0.272 1987 0.369 1988 0.466 1989 0.462 1990 0.569 1991 0.611 1992 0.831 1993 0.983 1994 1.632 1995 2.855 1996 3.047 1997 3.508 1998 5.373 1999 6.89 2000 9.332 2001 11.396 2002 12.704 2003 13.953 2004 15.863 2005 18.491 2006 20.365 2007 21.897 2008 24.075 2009 25.9 2010 27.524 2011 30.221 2012 40.67 2013 50.227 2014 62.358 2015 77.857 2016 93.405 2017 100 2018 109.892 2019 119.049 2020 128.246 2021 136.818 2022 144.941 2023 152.765 2024 160.353