Year Number 1970 171500 1971 188000 1972 216800 1973 340800 1974 382800 1975 361500 1976 449600 1977 237300 1978 363300 1979 377400 1980 392500 1981 408700 1982 391300 1983 435500 1984 479200 1985 558700 1986 611300 1987 655800 1988 720900 1989 760500 1990 794400 1991 759900 1992 721400 1993 769500 1994 753500 1995 740400 1996 778600 1997 835700 1998 1138400 1999 1357800 2000 1554949 2001 1418183 2002 1599843 2003 1678160 2004 2005473 2005 2424382 2006 2685148 2007 2857464 2008 2880546 2009 2948920 2010 4039583 2011 4508698.01161552 2012 4653459.73514364 2013 4516500 2014 4448530.52817802 2015 4569473 2016 4848016 2017 5109576 2018 5905365.1234425 2019 6417534.056 2020 1865768 2021 2459106