Year Number 1970 362032.8 1971 387934.3 1972 388139.3 1973 457458.5 1974 482646.3 1975 494085.1 1976 513129.1 1977 535178.5 1978 573663.2 1979 626642.1 1980 673704.1 1981 757585.8 1982 805536.7 1983 856546.3 1984 889092.4 1985 922568.6 1986 858488.9 1987 873226.1 1988 862242.3 1989 846893.9 1990 785472 1991 741231.8 1992 721739.6 1993 711970.6 1994 719303.6 1995 691238.9 1996 720491.6 1997 761264.6 1998 798460.5 1999 842065.8 2000 900309.4 2001 926642.9 2002 938772.6 2003 1033511 2004 1174739 2005 1411874 2006 1610060 2007 1842522 2008 1997035 2009 2206550 2010 2337275 2011 2461866 2012 2574039 2013 2558378 2014 2513976 2015 2404152 2016 2375200 2017 2390357 2018 2214384