| Year | Value | | 2024 | 138.10818546079 | | 2023 | 134.8955352032 | | 2022 | 129.85832856325 | | 2021 | 121.58700629651 | | 2020 | 117.5944476245 | | 2019 | 116.75729822553 | | 2018 | 114.52489982828 | | 2017 | 111.9848311391 | | 2016 | 110.22467086434 | | 2015 | 108.67200915856 | | 2014 | 107.46279336005 | | 2013 | 105.4522037779 | | 2012 | 104.47195191757 | | 2011 | 102.91213508872 | | 2010 | 100 | | 2009 | 98.25414997138 | | 2008 | 97.960789925587 | | 2007 | 95.692615912994 | | 2006 | 93.689181453921 | | 2005 | 91.850314825415 | | 2004 | 89.861190612478 | | 2003 | 88.22266742988 | | 2002 | 85.854321694333 | | 2001 | 83.958214081282 | | 2000 | 81.890383514596 | | 1999 | 79.722381224957 | | 1998 | 78.362907842015 | | 1997 | 77.590154550658 | | 1996 | 76.352318259874 | | 1995 | 75.171722953635 | | 1994 | 73.590440755581 | | 1993 | 73.468803663423 | | 1992 | 72.123640526617 | | 1991 | 71.064682312536 | | 1990 | 67.279622209502 | | 1989 | 64.21007441328 | | 1988 | 61.161991986262 | | 1987 | 58.793646250715 | | 1986 | 56.339439038352 | | 1985 | 54.071265025758 | | 1984 | 52.010589582141 | | 1983 | 49.864052661706 | | 1982 | 47.102175157413 | | 1981 | 42.522896393818 | | 1980 | 37.807670291929 | | 1979 | 34.330280480824 | | 1978 | 31.453921007441 | | 1977 | 28.863766456783 | | 1976 | 26.731539782484 |
|