Year Total 1965 3670000 1966 4084000 1967 3620000 1968 3935000 1969 4180000 1970 4630000 1971 4760000 1972 5108000 1973 5221000 1974 5694000 1975 5913000 1976 6203000 1977 6391000 1978 6484000 1979 6645000 1980 7034000 1981 7180000 1982 8063000 1983 8872000 1984 9969000 1985 11933000 1986 13132000 1987 13864000 1988 13404000 1989 15105000 1990 16038000 1991 17133000 1992 17071000 1993 15796000 1994 15843000 1995 16538000 1996 18603000 1997 20782000 1998 21562000 1999 20034000 2000 22461000 2001 18453000 2002 19273000 2003 20816000 2004 22086000 2005 22157000 2006 26168000 2007 29464000 2008 29596000 2009 30898000 2010 31438000 2011 33879000 2012 36495000 2013 31564000 2014 36126000 2015 34740000 2016 38435000