Year	Number of
1990	8924
1991	12480
1992	14910
1993	16690
1994	17760
1995	18310
1996	18500
1997	18410
1998	18170
1999	17740
2000	17220
2001	16600
2002	16090
2003	15690
2004	15510
2005	15470
2006	15370
2007	15480