Year Total 1965 17371000 1966 18004000 1967 18508000 1968 19062000 1969 19714000 1970 19922000 1971 19997000 1972 20888000 1973 21753000 1974 22706000 1975 23434000 1976 24230000 1977 25295000 1978 25955000 1979 27132000 1980 27925000 1981 28645000 1982 28949000 1983 28939000 1984 30602000 1985 31654000 1986 32458000 1987 33823000 1988 35577000 1989 37314000 1990 38207000 1991 38974000 1992 39205000 1993 39457000 1994 40263000 1995 41631000 1996 43333000 1997 45525000 1998 47557000 1999 47809000 2000 48004000 2001 47452000 2002 48494000 2003 49888000 2004 52032000 2005 51742000 2006 53115000 2007 52661000 2008 54853000 2009 53121000 2010 49390000 2011 48112000 2012 45093000 2013 43000000 2014 42643000 2015 44087000 2016 43807000