| Year | Value | | 2022 | 17,838,536 | | 2021 | 17,468,992 | | 2020 | 17,124,410 | | 2019 | 16,797,144 | | 2018 | 16,485,735 | | 2017 | 16,202,303 | | 2016 | 15,931,090 | | 2015 | 15,653,791 | | 2014 | 15,379,949 | | 2013 | 15,119,939 | | 2012 | 14,882,226 | | 2011 | 14,660,638 | | 2010 | 14,268,347 | | 2009 | 13,867,711 | | 2008 | 13,633,078 | | 2007 | 13,414,449 | | 2006 | 13,224,211 | | 2005 | 13,064,209 | | 2004 | 12,915,830 | | 2003 | 12,772,007 | | 2002 | 12,628,787 | | 2001 | 12,480,030 | | 2000 | 12,329,367 | | 1999 | 12,167,284 | | 1998 | 12,042,917 | | 1997 | 11,855,408 | | 1996 | 11,638,190 | | 1995 | 11,420,846 | | 1994 | 11,217,895 | | 1993 | 11,000,036 | | 1992 | 10,749,426 | | 1991 | 10,493,445 | | 1990 | 10,264,719 | | 1989 | 10,053,600 | | 1988 | 9,794,656 | | 1987 | 9,525,465 | | 1986 | 9,258,855 | | 1985 | 9,002,554 | | 1984 | 8,760,722 | | 1983 | 8,532,901 | | 1982 | 8,317,532 | | 1981 | 8,111,179 | | 1980 | 7,910,937 | | 1979 | 7,711,422 | | 1978 | 7,504,208 | | 1977 | 7,288,135 | | 1976 | 7,071,377 | | 1975 | 6,860,086 | | 1974 | 6,655,552 | | 1973 | 6,457,663 | | 1972 | 6,266,231 | | 1971 | 6,081,173 | | 1970 | 5,898,546 | | 1969 | 5,710,860 | | 1968 | 5,518,230 | | 1967 | 5,325,586 | | 1966 | 5,134,735 | | 1965 | 4,944,594 | | 1964 | 4,756,230 | | 1963 | 4,572,505 | | 1962 | 4,392,408 | | 1961 | 4,217,381 | | 1960 | 4,055,739 |
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