| Year | Value | | 2022 | 28,431,907 | | 2021 | 27,291,565 | | 2020 | 26,029,064 | | 2019 | 24,650,400 | | 2018 | 23,488,145 | | 2017 | 22,599,037 | | 2016 | 21,864,793 | | 2015 | 21,317,137 | | 2014 | 20,922,549 | | 2013 | 20,651,306 | | 2012 | 20,448,486 | | 2011 | 20,183,665 | | 2010 | 19,808,676 | | 2009 | 19,336,219 | | 2008 | 18,766,954 | | 2007 | 18,158,269 | | 2006 | 17,600,073 | | 2005 | 17,152,258 | | 2004 | 16,785,965 | | 2003 | 16,454,786 | | 2002 | 16,111,204 | | 2001 | 15,737,060 | | 2000 | 15,336,142 | | 1999 | 14,920,050 | | 1998 | 14,502,358 | | 1997 | 14,072,012 | | 1996 | 13,636,156 | | 1995 | 13,186,641 | | 1994 | 12,741,686 | | 1993 | 12,313,909 | | 1992 | 11,885,800 | | 1991 | 11,476,350 | | 1990 | 11,137,455 | | 1989 | 10,894,403 | | 1988 | 10,697,134 | | 1987 | 10,556,499 | | 1986 | 10,457,110 | | 1985 | 10,318,768 | | 1984 | 10,115,587 | | 1983 | 9,878,542 | | 1982 | 9,625,197 | | 1981 | 9,354,534 | | 1980 | 9,091,062 | | 1979 | 8,824,708 | | 1978 | 8,539,191 | | 1977 | 8,238,430 | | 1976 | 7,942,319 | | 1975 | 7,674,627 | | 1974 | 7,452,904 | | 1973 | 7,270,728 | | 1972 | 7,118,273 | | 1971 | 6,974,256 | | 1970 | 6,792,670 | | 1969 | 6,575,384 | | 1968 | 6,321,955 | | 1967 | 6,036,661 | | 1966 | 5,771,661 | | 1965 | 5,563,615 | | 1964 | 5,412,070 | | 1963 | 5,347,845 | | 1962 | 5,337,513 | | 1961 | 5,293,415 | | 1960 | 5,193,205 |
|