Year	Number of
1990	25170
1991	24720
1992	24270
1993	23830
1994	23370
1995	22910
1996	20730
1997	20660
1998	20290
1999	20180
2000	19820
2001	19400
2002	19320
2003	19260
2004	19030
2005	18810
2006	18900
2007	18840