| Year | Value | | 2022 | 3,387 | | 2021 | 3,402 | | 2020 | 3,443 | | 2019 | 3,468 | | 2018 | 3,477 | | 2017 | 3,487 | | 2016 | 3,519 | | 2015 | 3,576 | | 2014 | 3,653 | | 2013 | 3,741 | | 2012 | 3,812 | | 2011 | 3,832 | | 2010 | 3,820 | | 2009 | 3,789 | | 2008 | 3,731 | | 2007 | 3,656 | | 2006 | 3,552 | | 2005 | 3,431 | | 2004 | 3,323 | | 2003 | 3,226 | | 2002 | 3,111 | | 2001 | 2,980 | | 2000 | 2,834 | | 1999 | 2,669 | | 1998 | 2,501 | | 1997 | 2,359 | | 1996 | 2,259 | | 1995 | 2,162 | | 1994 | 2,055 | | 1993 | 1,960 | | 1992 | 1,877 | | 1991 | 1,799 | | 1990 | 1,720 | | 1989 | 1,625 | | 1988 | 1,525 | | 1987 | 1,430 | | 1986 | 1,352 | | 1985 | 1,294 | | 1984 | 1,264 | | 1983 | 1,255 | | 1982 | 1,259 | | 1981 | 1,276 | | 1980 | 1,300 | | 1979 | 1,331 | | 1978 | 1,364 | | 1977 | 1,397 | | 1976 | 1,427 | | 1975 | 1,451 | | 1974 | 1,472 | | 1973 | 1,486 | | 1972 | 1,492 | | 1971 | 1,492 | | 1970 | 1,488 | | 1969 | 1,470 | | 1968 | 1,437 | | 1967 | 1,409 | | 1966 | 1,389 | | 1965 | 1,373 | | 1964 | 1,365 | | 1963 | 1,377 | | 1962 | 1,397 | | 1961 | 1,407 | | 1960 | 1,405 |
|