Year Total 1965 4435000 1966 4839000 1967 5689000 1968 5815000 1969 6190000 1970 6707000 1971 7405000 1972 8586000 1973 10000000 1974 9390000 1975 9943000 1976 10574000 1977 10764000 1978 11702000 1979 12383000 1980 12400000 1981 11920000 1982 11901000 1983 11414000 1984 11689000 1985 11978000 1986 12159000 1987 13205000 1988 13661000 1989 14961000 1990 14679000 1991 14865000 1992 15189000 1993 15477000 1994 15987000 1995 16569000 1996 17364000 1997 17654000 1998 18642000 1999 18012000 2000 18883000 2001 19302000 2002 19378000 2003 20293000 2004 20116000 2005 20138000 2006 21256000 2007 21382000 2008 20358000 2009 19471000 2010 18085000 2011 17001000 2012 15267000 2013 14498000 2014 14382000 2015 14918000 2016 15377000