Year	Number of
1990	3871000
1993	4686000
1994	4737000
1996	6183000
1997	2761000
1998	2986000
1999	4193000
2000	3775000
2001	3824000
2002	2784000
2003	3359000
2004	2871000
2005	3688000
2006	4204000