| Year | Value | | 2022 | 12,181,776 | | 2021 | 12,111,969 | | 2020 | 12,028,921 | | 2019 | 11,844,340 | | 2018 | 11,685,978 | | 2017 | 11,457,607 | | 2016 | 11,336,881 | | 2015 | 11,098,332 | | 2014 | 10,597,060 | | 2013 | 10,222,697 | | 2012 | 10,096,452 | | 2011 | 9,858,123 | | 2010 | 9,490,014 | | 2009 | 9,216,930 | | 2008 | 8,892,844 | | 2007 | 8,422,860 | | 2006 | 7,879,146 | | 2005 | 7,500,767 | | 2004 | 7,264,674 | | 2003 | 6,979,118 | | 2002 | 6,693,764 | | 2001 | 6,507,443 | | 2000 | 6,363,132 | | 1999 | 6,210,726 | | 1998 | 6,081,278 | | 1997 | 5,986,258 | | 1996 | 5,934,550 | | 1995 | 5,914,578 | | 1994 | 5,971,723 | | 1993 | 6,039,767 | | 1992 | 6,096,396 | | 1991 | 6,192,691 | | 1990 | 6,247,159 | | 1989 | 6,212,471 | | 1988 | 6,307,653 | | 1987 | 6,429,713 | | 1986 | 6,369,521 | | 1985 | 6,357,615 | | 1984 | 6,425,940 | | 1983 | 6,288,238 | | 1982 | 6,075,316 | | 1981 | 6,003,001 | | 1980 | 5,882,292 | | 1979 | 5,685,725 | | 1978 | 5,572,803 | | 1977 | 5,584,061 | | 1976 | 5,595,339 | | 1975 | 5,582,091 | | 1974 | 5,541,196 | | 1973 | 5,475,033 | | 1972 | 5,370,834 | | 1971 | 5,194,067 | | 1970 | 5,017,405 | | 1969 | 4,881,673 | | 1968 | 4,702,055 | | 1967 | 4,554,108 | | 1966 | 4,447,937 | | 1965 | 4,307,529 | | 1964 | 4,203,860 | | 1963 | 4,201,917 | | 1962 | 4,180,964 | | 1961 | 4,126,894 | | 1960 | 4,119,132 |
|