Year	Number of
1990	31220
1991	30040
1992	28890
1993	27770
1994	26690
1995	25640
1996	24860
1997	23850
1998	22910
1999	21030
2000	19350
2001	18950
2002	15800
2003	15600
2004	14930
2005	15010
2006	14670
2007	13910