Year	Number of
1990	28850
1991	29360
1992	29840
1993	30280
1994	30700
1995	31090
1996	31100
1997	37520
1998	37800
1999	38010
2000	31340
2001	31650
2002	32030
2003	31670
2004	32160
2005	32230
2006	32100
2007	32250