Year Number 1970 305200 1971 292500 1972 291400 1973 348900 1974 371900 1975 363800 1976 352900 1977 348000 1978 349200 1979 357700 1980 382000 1981 383600 1982 344000 1983 325300 1984 343600 1985 351900 1986 343000 1987 333800 1988 380900 1989 370200 1990 346800 1991 257800 1992 258700 1993 243700 1994 253500 1995 282800 1996 305800 1997 310800 1998 317800 1999 319600 2000 963468 2001 982013 2002 263906 2003 1036092 2004 988755 2005 1018480 2006 1042100 2007 1188947 2008 1200361 2009 1198381 2010 1234528.61925597 2011 1245743.61579713 2012 1280198.18557714 2013 1263297.33686341 2014 1290419 2015 1322033 2016 1359442 2017 1443818 2018 1250460 2019 1215983 2020 511637 2021 571070.076