Year Number 1970 220000 1971 228000 1972 224700 1973 228200 1974 220100 1975 253200 1976 281800 1977 262600 1978 276000 1979 301000 1980 321400 1981 334600 1982 323400 1983 329300 1984 326600 1985 334200 1986 304800 1987 306600 1988 300500 1989 311500 1990 317100 1991 321900 1992 302300 1993 302700 1994 303500 1995 278900 1996 293600 1997 337600 1998 332300 1999 337800 2000 354035 2001 349026 2002 320253 2003 338510 2004 356660 2005 380427 2006 378262 2007 421479 2008 366757 2009 373213 2010 591685.6200196507 2011 638799.4444942056 2012 661095.2497254368 2013 703872.772 2014 680337.1268037994 2015 720955 2016 720715 2017 781350 2018 862254.2111460221 2019 876670.0900000001 2020 378675.5464 2021 534427.861