Year	Number
1973	8750
1974	8707
1975	8691
1976	8684
1977	8706
1978	8673
1979	8805
1980	8791
1981	9094
1982	9270
1983	9386
1984	9506
1985	9579
1986	9599
1987	9602
1988	9512
1989	9325
1990	9015
1991	8748
1992	8554
1993	8305
1994	8015
1995	7689
1996	7024
1997	6554
1998	6247
1999	5916
2000	5719
2001	5495
2002	5448
2003	5539
2004	5629
2005	5663
2006	5720
2007	5641
2008	5441
2009	4940
2010	4356
2011	3786
2012	3274
2013	2811
2014	2497
2015	2206
2016	2023
2017	1861
2018	1866
2019	1898
2020	2046
2021	1992
2022	1890