Year | Value | 2022 | 20,680 | 2021 | 20,943 | 2020 | 21,384 | 2019 | 21,964 | 2018 | 22,554 | 2017 | 22,952 | 2016 | 23,125 | 2015 | 23,161 | 2014 | 23,066 | 2013 | 22,855 | 2012 | 22,552 | 2011 | 22,220 | 2010 | 21,953 | 2009 | 21,733 | 2008 | 21,441 | 2007 | 21,101 | 2006 | 20,891 | 2005 | 20,727 | 2004 | 20,518 | 2003 | 20,494 | 2002 | 20,687 | 2001 | 20,928 | 2000 | 21,330 | 1999 | 21,953 | 1998 | 22,562 | 1997 | 23,161 | 1996 | 23,656 | 1995 | 24,028 | 1994 | 24,295 | 1993 | 24,481 | 1992 | 24,568 | 1991 | 24,683 | 1990 | 24,868 | 1989 | 25,040 | 1988 | 25,162 | 1987 | 25,191 | 1986 | 25,068 | 1985 | 24,750 | 1984 | 24,197 | 1983 | 23,381 | 1982 | 22,305 | 1981 | 21,033 | 1980 | 19,671 | 1979 | 18,264 | 1978 | 16,895 | 1977 | 15,775 | 1976 | 15,123 | 1975 | 15,092 | 1974 | 15,615 | 1973 | 16,451 | 1972 | 17,358 | 1971 | 18,170 | 1970 | 18,837 | 1969 | 19,292 | 1968 | 19,474 | 1967 | 19,440 | 1966 | 19,257 | 1965 | 19,021 | 1964 | 18,756 | 1963 | 18,421 | 1962 | 17,958 | 1961 | 17,340 | 1960 | 16,558 |
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