Year Total 1985 28173000 1986 31439000 1987 32416000 1988 32498000 1989 33475000 1990 33231000 1991 34112000 1992 34862000 1993 36680000 1994 38428000 1995 39550000 1996 39891000 1997 41737000 1998 44625000 1999 45270000 2000 45949000 2001 46763000 2002 46729000 2003 46822000 2004 48759000 2005 48613000 2006 50978000 2007 52371000 2008 51991000 2009 50016000 2010 48960000 2011 51312000 2012 51231000 2013 51196000 2014 51562000 2015 51974000 2016 56489000