| Year | Value | | 2022 | 20,791,379 | | 2021 | 19,866,193 | | 2020 | 19,532,032 | | 2019 | 19,333,304 | | 2018 | 18,886,006 | | 2017 | 18,408,318 | | 2016 | 18,035,324 | | 2015 | 17,622,785 | | 2014 | 17,166,261 | | 2013 | 16,778,698 | | 2012 | 16,429,185 | | 2011 | 16,093,310 | | 2010 | 15,850,090 | | 2009 | 15,690,373 | | 2008 | 15,511,082 | | 2007 | 15,274,425 | | 2006 | 14,987,333 | | 2005 | 14,571,615 | | 2004 | 14,041,594 | | 2003 | 13,578,585 | | 2002 | 13,182,916 | | 2001 | 12,746,965 | | 2000 | 12,403,825 | | 1999 | 12,075,442 | | 1998 | 11,484,692 | | 1997 | 10,771,776 | | 1996 | 10,148,695 | | 1995 | 9,583,895 | | 1994 | 9,270,813 | | 1993 | 9,352,127 | | 1992 | 9,626,824 | | 1991 | 9,852,582 | | 1990 | 9,957,925 | | 1989 | 9,923,514 | | 1988 | 9,775,281 | | 1987 | 9,583,112 | | 1986 | 9,359,257 | | 1985 | 9,143,794 | | 1984 | 8,928,290 | | 1983 | 8,690,373 | | 1982 | 8,473,632 | | 1981 | 8,290,651 | | 1980 | 8,104,024 | | 1979 | 7,895,710 | | 1978 | 7,680,181 | | 1977 | 7,421,545 | | 1976 | 7,146,166 | | 1975 | 6,900,019 | | 1974 | 6,669,489 | | 1973 | 6,466,478 | | 1972 | 6,280,373 | | 1971 | 6,122,125 | | 1970 | 5,990,937 | | 1969 | 5,913,510 | | 1968 | 5,871,753 | | 1967 | 5,832,130 | | 1966 | 5,759,469 | | 1965 | 5,677,014 | | 1964 | 5,592,622 | | 1963 | 5,487,729 | | 1962 | 5,388,021 | | 1961 | 5,293,294 | | 1960 | 5,191,938 |
|