Year Number 1970 157700 1971 174900 1972 184900 1973 201500 1974 232400 1975 242100 1976 284900 1977 311300 1978 341300 1979 341700 1980 353100 1981 361800 1982 357800 1983 389900 1984 394100 1985 382900 1986 389900 1987 381200 1988 406400 1989 414200 1990 415100 1991 385000 1992 441300 1993 467800 1994 491800 1995 483000 1996 519600 1997 545200 1998 535600 1999 571700 2000 613217 2001 665244 2002 621484 2003 683657 2004 701240 2005 590992 2006 648841 2007 707006 2008 680702 2009 1003079 2010 1267722.2842383632 2011 1292819.150162648 2012 1353694.091937992 2013 1427157.5 2014 1501061.1416163929 2015 1561886 2016 1691849 2017 1780821.4679999999 2018 1812409.753530167 2019 1844219.2719999999 2020 811860.4600000001 2021 1087594.114