Year Total 1965 5409000 1966 5620000 1967 6089000 1968 7620000 1969 8387000 1970 8864000 1971 9423000 1972 10578000 1973 11742000 1974 12390000 1975 13491000 1976 14902000 1977 15941000 1978 17058000 1979 17390000 1980 17126000 1981 16052000 1982 15165000 1983 15663000 1984 16076000 1985 16351000 1986 16879000 1987 17080000 1988 17504000 1989 17345000 1990 15843000 1991 14930000 1992 13597000 1993 14039000 1994 14808000 1995 14935000 1996 17470000 1997 18186000 1998 20806000 1999 21762000 2000 19961000 2001 19484000 2002 19857000 2003 20208000 2004 21554000 2005 22391000 2006 23336000 2007 24173000 2008 25286000 2009 25258000 2010 26706000 2011 26617000 2012 25691000 2013 23809000 2014 23875000 2015 24942000 2016 27202000