Year Number 1971 531934 1972 534895 1973 528541 1974 520761 1975 513027 1976 501843 1977 492723 1978 466933 1979 445103 1980 420935 1981 400397 1982 384986 1983 367691 1984 354479 1985 342779 1986 343823 1987 343013 1988 350734 1989 360542 1990 367006 1991 370210 1992 378676 1993 382663 1994 381628 1995 381363 1996 382005 1997 381927 1998 385309 1999 388777 2000 392407 2001 392339 2002 386484 2003 379920 2004 372963 2005 362822 2006 355293 2007 347249 2008 337448 2009 331565 2010 328015 2011 326351 2012 326955 2013 327187 2014 327246.84375 2015 327816.84375 2016 329031.5 2017 334933.15625 2018 339021.84375 2019 342064 2020 343980.5 2021 346610.5 2022 347620.5