Year Index 1980 0.12 1981 0.134 1982 0.134 1983 0.144 1984 0.148 1985 0.148 1986 0.169 1987 0.211 1988 0.298 1989 0.432 1990 0.606 1991 0.926 1992 1.179 1993 1.564 1994 2.744 1995 3.757 1996 5.699 1997 10.286 1998 12.43 1999 13.623 2000 14.931 2001 16.338 2002 17.813 2003 19.59 2004 22.576 2005 26.459 2006 32.957 2007 42.04 2008 52.48 2009 60.923 2010 68.776 2011 76.987 2012 84.999 2013 91.063 2014 96.915 2015 100.752 2016 105.913 2017 114.058 2018 124.374 2019 131.782 2020 138.371 2021 143.906 2022 148.223 2023 152.67 2024 157.25