Year Total 1990 500000 1991 650000 1992 950000 1993 1170000 1994 1700000 1995 2600000 1996 3500000 1997 4400000 1998 5100000 1999 5500000 2000 9300000 2001 11000000 2002 13000000 2003 13000000 2004 15000000 2005 17400000 2006 19000000