Year Total 1990 1595000 1991 1967000 1992 2500000 1993 3050000 1994 3875000 1995 4857000 1996 6304000 1997 6931000 1998 8269000 1999 11530000 2000 18620000 2001 22500000 2002 23500000 2003 24250000 2004 24860000 2005 25680000 2006 26120000