| Year | Value | | 2022 | 2,515 | | 2021 | 2,456 | | 2020 | 2,392 | | 2019 | 2,326 | | 2018 | 2,270 | | 2017 | 2,216 | | 2016 | 2,148 | | 2015 | 2,075 | | 2014 | 2,000 | | 2013 | 1,916 | | 2012 | 1,833 | | 2011 | 1,770 | | 2010 | 1,719 | | 2009 | 1,666 | | 2008 | 1,606 | | 2007 | 1,549 | | 2006 | 1,489 | | 2005 | 1,429 | | 2004 | 1,375 | | 2003 | 1,326 | | 2002 | 1,285 | | 2001 | 1,256 | | 2000 | 1,231 | | 1999 | 1,220 | | 1998 | 1,224 | | 1997 | 1,229 | | 1996 | 1,228 | | 1995 | 1,225 | | 1994 | 1,220 | | 1993 | 1,213 | | 1992 | 1,207 | | 1991 | 1,203 | | 1990 | 1,201 | | 1989 | 1,188 | | 1988 | 1,160 | | 1987 | 1,130 | | 1986 | 1,094 | | 1985 | 1,054 | | 1984 | 1,013 | | 1983 | 970 | | 1982 | 929 | | 1981 | 892 | | 1980 | 858 | | 1979 | 737 | | 1978 | 590 | | 1977 | 541 | | 1976 | 531 | | 1975 | 527 | | 1974 | 529 | | 1973 | 537 | | 1972 | 546 | | 1971 | 551 | | 1970 | 552 | | 1969 | 551 | | 1968 | 546 | | 1967 | 540 | | 1966 | 538 | | 1965 | 541 | | 1964 | 547 | | 1963 | 556 | | 1962 | 566 | | 1961 | 576 | | 1960 | 585 |
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