Year	Number of
1980	24880
1981	28640
1982	28100
1983	26940
1984	22280
1985	26790
1986	27550
1987	27160
1988	25720
1989	26760
1990	27660
1991	27640
1992	25400
1993	27630
1994	30320
1995	29830
1996	31770
1997	30230
1998	29090
1999	29850
2000	28850
2001	28280
2002	29800
2003	26790
2004	25910
2005	26270
2006	26100
2007	25560