Year Total 1970 24004000 1971 33176000 1972 44234000 1973 53788000 1974 63772000 1975 69074000 1976 73803000 1977 74042000 1978 67784000 1979 71081000 1980 68740000 1981 63820000 1982 54576000 1983 58111000 1984 58828000 1985 61598000 1986 56320000 1987 56415000 1988 49799000 1989 54433000 1990 54935000 1991 62052000 1992 62482000 1993 63724000 1994 60189000 1995 60858000 1996 68883000 1997 61001000 1998 58183000 1999 54122000 2000 52188000 2001 56033000 2002 54218000 2003 52212000 2004 61574000 2005 56248000 2006 55388000 2007 54433000 2008 59879000 2009 56415000 2010 63437000 2011 57729000 2012 57419000 2013 61766000 2014 52116000 2015 39004000 2016 36137000