Year Number 1971 509691 1972 521167 1973 516954 1974 516979 1975 508205 1976 419808 1977 431090 1978 437675 1979 446041 1980 447643 1981 449322 1982 446341 1983 439471 1984 441950 1985 434507 1986 424076 1987 410807 1988 406835 1989 409414 1990 418209 1991 426864 1992 446207 1993 443831 1994 455300 1995 454707 1996 460878 1997 469933 1998 469495 1999 479882 2000 494095 2001 499882 2002 501689 2003 508063 2004 425966 2005 430596 2006 432565 2007 432607 2008 431233 2009 428332 2010 426710 2011 422872 2012 415505 2013 541021 2014 536925 2015 540067 2016 539816 2017 543436 2018 546469 2019 514823 2020 513900 2021 520297 2022 533496