| Year | Value | | 2022 | 4,934 | | 2021 | 4,911 | | 2020 | 4,835 | | 2019 | 4,696 | | 2018 | 4,507 | | 2017 | 4,397 | | 2016 | 4,460 | | 2015 | 4,534 | | 2014 | 4,565 | | 2013 | 4,605 | | 2012 | 4,637 | | 2011 | 4,690 | | 2010 | 4,745 | | 2009 | 4,774 | | 2008 | 4,781 | | 2007 | 4,753 | | 2006 | 4,672 | | 2005 | 4,568 | | 2004 | 4,462 | | 2003 | 4,345 | | 2002 | 4,234 | | 2001 | 4,157 | | 2000 | 4,124 | | 1999 | 4,094 | | 1998 | 4,023 | | 1997 | 3,913 | | 1996 | 3,816 | | 1995 | 3,796 | | 1994 | 3,826 | | 1993 | 3,898 | | 1992 | 4,019 | | 1991 | 4,186 | | 1990 | 4,381 | | 1989 | 4,553 | | 1988 | 4,717 | | 1987 | 4,836 | | 1986 | 4,851 | | 1985 | 4,902 | | 1984 | 5,054 | | 1983 | 5,169 | | 1982 | 5,188 | | 1981 | 5,130 | | 1980 | 5,062 | | 1979 | 4,991 | | 1978 | 4,892 | | 1977 | 4,779 | | 1976 | 4,657 | | 1975 | 4,521 | | 1974 | 4,366 | | 1973 | 4,187 | | 1972 | 3,974 | | 1971 | 3,817 | | 1970 | 3,889 | | 1969 | 4,134 | | 1968 | 4,397 | | 1967 | 4,622 | | 1966 | 4,710 | | 1965 | 4,615 | | 1964 | 4,367 | | 1963 | 4,023 | | 1962 | 3,658 | | 1961 | 3,373 | | 1960 | 3,276 |
|