Year Total 1990 900000 1991 1100000 1992 1200000 1993 1300000 1994 1600000 1995 2200000 1996 2600000 1997 3000000 1998 3500000 1999 4000000 2000 4500000 2001 5000000 2002 5556000 2003 6174000 2004 6861000 2005 7548000 2006 8000000