| Year | Value | | 2021 | 3,174.4160228033 | | 2020 | 3,127.151968483 | | 2019 | 3,404.1737727702 | | 2018 | 3,227.1861879887 | | 2017 | 3,126.3519678095 | | 2016 | 3,088.3918664908 | | 2015 | 3,023.2607470722 | | 2014 | 2,956.2352554486 | | 2013 | 2,881.9622265768 | | 2012 | 2,678.3840885143 | | 2011 | 2,395.0839096185 | | 2010 | 2,178.1816643684 | | 2009 | 1,893.197865771 | | 2008 | 1,936.1433809747 | | 2007 | 1,660.3093825133 | | 2006 | 1,406.3384861471 | | 2005 | 1,217.437905175 | | 2004 | 1,095.7030657528 | | 2003 | 1,052.680095504 | | 2002 | 1,043.8460700556 | | 2001 | 999.61712698979 | | 2000 | 1,084.954421362 | | 1999 | 1,176.8234549328 | | 1998 | 1,049.3753866557 | | 1997 | 1,245.4977295145 | | 1996 | 1,262.6950584397 | | 1995 | 1,143.790953778 | | 1994 | 1,011.2996745173 | | 1993 | 868.53642183788 | | 1992 | 868.5081935575 | | 1991 | 751.97033187875 | | 1990 | 741.86176620627 | | 1989 | 713.96396640699 | | 1988 | 646.60263979233 | | 1987 | 571.96113242687 | | 1986 | 519.77977393525 | | 1985 | 546.97843119145 | | 1984 | 574.91050267904 | | 1983 | 644.86175710497 | | 1982 | 744.67049609049 | | 1981 | 741.53592337322 | | 1980 | 690.12296994751 | | 1979 | 597.38789083617 | | 1978 | 515.44152528669 | | 1977 | 456.43209107685 | | 1976 | 404.67504841519 | | 1975 | 362.60473599495 | | 1974 | 342.66526111557 | | 1973 | 249.76700318107 | | 1972 | 200.78510581884 | | 1971 | 190.72306948105 |
|