Year Number 1970 4585300 1971 5013400 1972 5360200 1973 6261300 1974 6811800 1975 7320600 1976 8568400 1977 8749000 1978 9727500 1979 11279300 1980 13004500 1981 14195700 1982 14213900 1983 14332400 1984 14673200 1985 14994600 1986 13895900 1987 14099400 1988 14634800 1989 14534100 1990 14566000 1991 13966200 1992 13273000 1993 13633700 1994 14645200 1995 15054600 1996 15661100 1997 16093100 1998 15873700 1999 16774800 2000 17519022 2001 16753549 2002 16016828 2003 17470433 2004 19705682 2005 23121258 2006 25230306 2007 26657989 2008 27510500 2009 27184327 2010 37778795.13790186 2011 42254442.40103398 2012 45172846.80236844 2013 43445905.818 2014 43973716.11509803 2015 47353496 2016 49115389 2017 53627313.08 2018 64496529.360006236 2019 65822245.92023504 2020 24345492.602 2021 31345507.692