Year Number 1986 4628863 1987 3292669 1988 2196901 1989 1517692 1990 2657819 1991 2201453 1992 2480706 1993 3294787 1994 4338736 1995 5934937 1996 7309188 1997 8526571 1998 6952243 1999 5071870 2000 4725846 2001 4212502 2002 4142607 2003 3922742 2004 4165295 2005 4146726 2006 4699384 2007 3724073 2008 3589561 2009 3238443 2010 3423232 2011 3506037 2012 3123060 2013 3382712 2014 3012927 2015 2864500 2016 2666130 2017 2530310 2018 2546001