| Year | Value | | 2022 | 404,450 | | 2021 | 397,847 | | 2020 | 393,428 | | 2019 | 394,491 | | 2018 | 396,419 | | 2017 | 397,514 | | 2016 | 397,670 | | 2015 | 396,389 | | 2014 | 392,451 | | 2013 | 387,787 | | 2012 | 383,622 | | 2011 | 377,986 | | 2010 | 371,714 | | 2009 | 366,173 | | 2008 | 360,490 | | 2007 | 355,682 | | 2006 | 352,986 | | 2005 | 349,808 | | 2004 | 346,129 | | 2003 | 344,899 | | 2002 | 341,065 | | 2001 | 333,578 | | 2000 | 328,365 | | 1999 | 323,912 | | 1998 | 316,522 | | 1997 | 308,323 | | 1996 | 301,085 | | 1995 | 292,821 | | 1994 | 286,948 | | 1993 | 285,690 | | 1992 | 287,112 | | 1991 | 292,034 | | 1990 | 298,724 | | 1989 | 302,062 | | 1988 | 302,958 | | 1987 | 304,946 | | 1986 | 306,637 | | 1985 | 306,776 | | 1984 | 306,351 | | 1983 | 305,676 | | 1982 | 303,610 | | 1981 | 301,430 | | 1980 | 298,898 | | 1979 | 295,968 | | 1978 | 292,204 | | 1977 | 287,600 | | 1976 | 282,198 | | 1975 | 272,846 | | 1974 | 257,927 | | 1973 | 246,070 | | 1972 | 239,779 | | 1971 | 236,281 | | 1970 | 230,046 | | 1969 | 230,283 | | 1968 | 238,639 | | 1967 | 244,720 | | 1966 | 251,257 | | 1965 | 260,462 | | 1964 | 265,705 | | 1963 | 264,411 | | 1962 | 262,024 | | 1961 | 258,170 | | 1960 | 251,001 |
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