Year Total 1970 3137000 1971 3128000 1972 2899000 1973 3302000 1974 3653000 1975 4104000 1976 4185000 1977 4572000 1978 4698000 1979 5292000 1980 6462000 1981 7047000 1982 7686000 1983 7578000 1984 7776000 1985 7938000 1986 8514000 1987 9117000 1988 9666000 1989 10305000 1990 11007000 1991 11889000 1992 11664000 1993 13428000 1994 13689000 1995 14040000 1996 15255000 1997 15210000 1998 16020000 1999 18270000 2000 19350000 2001 20430000 2002 22149000 2003 27539000 2004 33065000 2005 35149000 2006 35913000 2007 36431000 2008 37302000 2009 37403000 2010 38100000 2011 38091000 2012 39446000 2013 38356000 2014 37710000 2015 37776000 2016 37378000