Year | Value | 2022 | 17,826,176 | 2021 | 18,253,255 | 2020 | 18,334,153 | 2019 | 18,370,296 | 2018 | 18,375,538 | 2017 | 18,376,132 | 2016 | 18,375,539 | 2015 | 18,385,857 | 2014 | 18,399,901 | 2013 | 18,415,399 | 2012 | 18,428,967 | 2011 | 18,432,087 | 2010 | 18,424,911 | 2009 | 18,479,746 | 2008 | 18,471,142 | 2007 | 18,476,559 | 2006 | 18,497,199 | 2005 | 18,518,319 | 2004 | 18,533,816 | 2003 | 18,551,268 | 2002 | 18,570,141 | 2001 | 18,585,200 | 2000 | 18,574,609 | 1999 | 18,757,096 | 1998 | 18,769,921 | 1997 | 18,772,067 | 1996 | 18,767,504 | 1995 | 18,761,167 | 1994 | 18,744,253 | 1993 | 18,712,487 | 1992 | 18,673,543 | 1991 | 18,626,452 | 1990 | 18,569,700 | 1989 | 18,504,522 | 1988 | 18,446,798 | 1987 | 18,376,265 | 1986 | 18,273,043 | 1985 | 18,147,381 | 1984 | 17,998,382 | 1983 | 17,832,093 | 1982 | 17,661,253 | 1981 | 17,496,846 | 1980 | 17,337,360 | 1979 | 17,176,794 | 1978 | 17,039,712 | 1977 | 16,904,741 | 1976 | 16,739,409 | 1975 | 16,566,334 | 1974 | 16,393,099 | 1973 | 16,228,047 | 1972 | 16,073,711 | 1971 | 15,934,423 | 1970 | 15,873,984 | 1969 | 15,817,111 | 1968 | 15,691,254 | 1967 | 15,537,724 | 1966 | 15,384,068 | 1965 | 15,262,754 | 1964 | 15,106,342 | 1963 | 14,890,384 | 1962 | 14,685,065 | 1961 | 14,507,503 | 1960 | 14,337,906 |
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