Year Number 1970 219700 1971 220700 1972 229300 1973 244200 1974 226300 1975 261900 1976 278300 1977 284800 1978 292700 1979 349600 1980 359200 1981 354900 1982 348700 1983 364100 1984 391700 1985 363700 1986 362100 1987 357200 1988 374600 1989 380100 1990 335600 1991 318200 1992 370600 1993 314300 1994 325000 1995 282000 1996 291500 1997 294000 1998 283900 1999 336700 2000 356575 2001 444450 2002 380683 2003 320117 2004 349270 2005 375959 2006 405791 2007 394482 2008 408405 2009 404042 2010 488403.85218270496 2011 543909.4012380647 2012 519697.5005371599 2013 556736.09 2014 533306.4526301174 2015 523455 2016 528016 2017 536379.38 2018 544673.4445437407 2019 545738.122 2020 283689.11799999996 2021 371452.766