Year Number 1970 6347400 1971 7505400 1972 8654900 1973 9964000 1974 10198100 1975 10959100 1976 11801100 1977 13328200 1978 15369000 1979 15683000 1980 15089000 1981 14601800 1982 14637600 1983 14538000 1984 14283900 1985 14850700 1986 15403500 1987 16553300 1988 18983200 1989 20270300 1990 21652000 1991 20944600 1992 23385800 1993 22279400 1994 22361300 1995 25765700 1996 27759200 1997 30315700 1998 31594100 1999 33559400 2000 39711776 2001 41469789 2002 40380629 2003 42506835 2004 45539952 2005 49855007 2006 53122464 2007 60664991 2008 55213716 2009 49289158 2010 52847712.6083233 2011 52736140.9250126 2012 48089178.327112 2013 48056735.818 2014 53069339 2015 60564041 2016 66674868 2017 71598374 2018 80706703 2019 88237165.272 2020 26557077.999 2021 43440479.727