Year Number 1986 5339728 1987 4302156 1988 3258184 1989 2792975 1990 2867863 1991 2885864 1992 3255326 1993 3796142 1994 4813004 1995 6229321 1996 7358602 1997 8535316 1998 6839728 1999 4489965 2000 4179665 2001 3789902 2002 3453140 2003 2866756 2004 3183250 2005 3000596 2006 3976604 2007 3268196 2008 2424776 2009 2656745 2010 2798213 2011 2571539 2012 2319502 2013 2402345 2014 2372699 2015 2329258 2016 2252122 2017 2167502 2018 2310029