Year	Number
1973	552826
1974	502676
1975	461335
1976	459531
1977	482350
1978	473866
1979	477515
1980	469877
1981	474104
1982	485990
1983	488823
1984	465731
1985	450759
1986	424813
1987	405662
1988	395346
1989	397907
1990	414372
1991	403367
1992	397166
1993	407991
1994	399211
1995	379398
1996	367708
1997	324441
1999	173362
2000	136636
2001	82040
2002	40729
2003	26918
2004	18786
2005	18179
2006	30385
2007	37900
2008	28816