| Year | Value | | 2022 | 18,383,330 | | 2021 | 18,578,739 | | 2020 | 18,858,820 | | 2019 | 19,052,873 | | 2018 | 19,111,755 | | 2017 | 19,159,845 | | 2016 | 19,191,060 | | 2015 | 19,214,009 | | 2014 | 19,260,385 | | 2013 | 19,251,711 | | 2012 | 19,125,006 | | 2011 | 18,895,058 | | 2010 | 18,520,635 | | 2009 | 17,967,658 | | 2008 | 17,316,240 | | 2007 | 16,611,202 | | 2006 | 15,902,488 | | 2005 | 15,252,603 | | 2004 | 14,657,129 | | 2003 | 14,108,274 | | 2002 | 13,631,071 | | 2001 | 13,183,308 | | 2000 | 12,737,463 | | 1999 | 12,343,858 | | 1998 | 11,992,256 | | 1997 | 11,658,073 | | 1996 | 11,337,178 | | 1995 | 11,033,025 | | 1994 | 10,734,083 | | 1993 | 10,493,233 | | 1992 | 10,266,660 | | 1991 | 9,959,946 | | 1990 | 9,596,703 | | 1989 | 9,186,140 | | 1988 | 8,879,258 | | 1987 | 8,570,282 | | 1986 | 8,277,971 | | 1985 | 8,006,557 | | 1984 | 7,740,602 | | 1983 | 7,485,976 | | 1982 | 7,242,752 | | 1981 | 6,956,046 | | 1980 | 6,662,124 | | 1979 | 6,412,026 | | 1978 | 6,170,862 | | 1977 | 5,929,204 | | 1976 | 5,675,404 | | 1975 | 5,423,155 | | 1974 | 5,174,702 | | 1973 | 4,936,857 | | 1972 | 4,720,883 | | 1971 | 4,529,246 | | 1970 | 4,370,176 | | 1969 | 4,249,492 | | 1968 | 4,167,885 | | 1967 | 4,117,676 | | 1966 | 4,083,333 | | 1965 | 4,053,110 | | 1964 | 4,018,604 | | 1963 | 3,977,959 | | 1962 | 3,930,230 | | 1961 | 3,877,855 | | 1960 | 3,829,751 |
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