Year Number 1970 1519000 1971 1659500 1972 1868100 1973 2313800 1974 2763600 1975 2936400 1976 2998800 1977 3076800 1978 3211200 1979 3783700 1980 4116000 1981 4159800 1982 4091200 1983 3951800 1984 4461400 1985 4337300 1986 3825000 1987 4386900 1988 5125900 1989 5641500 1990 5364900 1991 4818600 1992 4685000 1993 5581500 1994 5801600 1995 6395500 1996 7183100 1997 7274200 1998 6479500 1999 7403800 2000 8000757 2001 7948374 2002 8052660 2003 9159815 2004 9878598 2005 11844657 2006 12932671 2007 12870324 2008 13135437 2009 12503629 2010 15781210 2011 16407784.9571682 2012 17571565.2032155 2013 16311250 2014 17026643.2191223 2015 18882898 2016 19744932 2017 20821044 2018 24660386 2019 26211258 2020 8304771.044 2021 9321575.836