Year	Number of
1990	11120
1991	13790
1992	16090
1993	18480
1994	20800
1995	23170
1996	25260
1997	27300
1998	15020
1999	16720
2000	20160
2001	21460
2002	23670
2003	27860
2004	27590
2005	28640
2006	29050
2007	28410