Year Index 1980 0.076 1981 0.153 1982 0.178 1983 0.432 1984 0.458 1985 0.547 1986 0.73 1987 0.979 1988 1.239 1989 1.616 1990 2.197 1991 2.422 1992 2.745 1993 3.504 1994 4.702 1995 8.032 1996 10.13 1997 12.373 1998 14.322 1999 16.297 2000 22.904 2001 27.78 2002 31.994 2003 39.533 2004 44.189 2005 50.745 2006 56.288 2007 63.464 2008 74.973 2009 82.064 2010 87.701 2011 95.042 2012 102.764 2013 116.632 2014 136.445 2015 160.584 2016 185.253 2017 207.152 2018 226.676 2019 246.422 2020 266.136 2021 284.766 2022 303.276 2023 321.472 2024 340.76