Year | Value | 2023 | 16,871,609 | 2022 | 17,449,249 | 2021 | 20,294,308 | 2020 | 20,470,151 | 2019 | 20,602,695 | 2018 | 20,708,210 | 2017 | 20,790,678 | 2016 | 20,856,348 | 2015 | 20,907,349 | 2014 | 20,940,952 | 2013 | 21,023,906 | 2012 | 21,052,629 | 2011 | 21,086,669 | 2010 | 21,150,737 | 2009 | 21,225,759 | 2008 | 21,319,797 | 2007 | 21,443,946 | 2006 | 21,582,931 | 2005 | 21,743,359 | 2004 | 21,919,976 | 2003 | 22,098,936 | 2002 | 22,289,659 | 2001 | 22,518,464 | 2000 | 22,773,527 | 1999 | 23,015,947 | 1998 | 23,239,789 | 1997 | 23,452,138 | 1996 | 23,672,322 | 1995 | 23,888,454 | 1994 | 24,075,796 | 1993 | 24,188,217 | 1992 | 24,158,201 | 1991 | 24,063,460 | 1990 | 23,991,904 | 1989 | 23,912,317 | 1988 | 23,764,296 | 1987 | 23,629,909 | 1986 | 23,513,254 | 1985 | 23,404,699 | 1984 | 23,305,480 | 1983 | 23,191,365 | 1982 | 23,079,075 | 1981 | 22,974,102 | 1980 | 22,830,419 | 1979 | 22,690,061 | 1978 | 22,570,566 | 1977 | 22,470,056 | 1976 | 22,350,353 | 1975 | 22,211,757 | 1974 | 22,055,605 |
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