| Year | Value | | 2021 | 10,071.001532617 | | 2020 | 8,766.8743720727 | | 2019 | 10,107.733387741 | | 2018 | 10,407.89563975 | | 2017 | 9,846.9854375659 | | 2016 | 9,281.7500559938 | | 2015 | 9,484.118204131 | | 2014 | 11,013.652685545 | | 2013 | 10,632.985543939 | | 2012 | 10,075.727356814 | | 2011 | 9,577.2957071519 | | 2010 | 7,977.4132628538 | | 2009 | 7,364.3444991665 | | 2008 | 8,584.0829543885 | | 2007 | 7,219.60370558 | | 2006 | 6,067.4276924085 | | 2005 | 5,105.3035198693 | | 2004 | 4,485.7640185689 | | 2003 | 3,791.4173665962 | | 2002 | 3,065.2124361545 | | 2001 | 2,878.8361698544 | | 2000 | 2,800.5274862021 | | 1999 | 2,597.0343353591 | | 1998 | 2,563.6858603377 | | 1997 | 2,637.7123365099 | | 1996 | 2,542.7810447431 | | 1995 | 2,536.5956991894 | | 1994 | 2,243.6846073434 | | 1993 | 2,191.0700585289 | | 1992 | 2,302.0899132561 | | 1991 | 2,162.4973679001 | | 1990 | 1,946.1099739332 | | 1989 | 1,739.7599068578 | | 1988 | 1,782.0420800065 | | 1987 | 1,549.2547302825 | | 1986 | 1,440.2665485015 | | 1985 | 1,383.3336594309 | | 1984 | 1,456.6453034861 | | 1983 | 1,567.6369297789 | | 1982 | 1,696.3688500999 | | 1981 | 1,622.3747975194 | | 1980 | 1,348.2663501188 |
|