Year Total 1970 750000 1971 1324000 1972 1344000 1973 1562000 1974 1564000 1975 1494000 1976 1746000 1977 3510000 1978 5139000 1979 5499000 1980 6768000 1981 7974000 1982 8550000 1983 7524000 1984 9900000 1985 11907000 1986 13698000 1987 15201000 1988 15624000 1989 18342000 1990 18099000 1991 21429000 1992 19953000 1993 20691000 1994 24174000 1995 28188000 1996 30420000 1997 32679000 1998 33363000 1999 34641000 2000 34542000 2001 40446000 2002 39051000 2003 40311000 2004 41661000 2005 43011000 2006 43911000 2007 45261000 2008 45216000 2009 43956000 2010 46154000 2011 47077000 2012 48870000 2013 49140000 2014 48820000 2015 54163000 2016 55676000