Year Number 1970 152300 1971 160400 1972 157100 1973 155800 1974 150400 1975 173500 1976 193500 1977 161800 1978 170300 1979 188200 1980 204800 1981 211800 1982 206700 1983 208000 1984 207500 1985 211900 1986 195400 1987 203000 1988 202200 1989 220100 1990 232100 1991 227200 1992 220400 1993 233800 1994 233400 1995 212500 1996 231500 1997 259600 1998 253900 1999 268400 2000 282913 2001 288922 2002 267907 2003 289028 2004 300359 2005 321298 2006 319498 2007 359120 2008 318638 2009 327145 2010 470912.30005113594 2011 500629.94659704197 2012 514462.2894371635 2013 548834.772 2014 534810.3034944466 2015 556341 2016 562927 2017 630147 2018 705127.484622134 2019 717795.3 2020 286064.19739999995 2021 399895.84800000006