Year	Number
1970	9922
1971	10008
1972	9990
1973	10058
1974	10131
1975	10219
1976	10295
1977	9890
1978	9626
1979	9667
1980	9567
1981	9288
1982	9482
1983	9605
1984	9211
1985	8732
1986	8005
1987	7438
1988	6994
1989	6420
1990	6033
1991	5875
1992	5458
1993	5101
1994	4824
1995	4160
1996	3735
1997	3202
1998	2730
1999	2363
2000	2186
2001	2030
2002	1874
2003	1787
2004	1734
2005	1691
2006	1665
2007	1645
2008	1664
2009	1596
2010	1517
2011	1359
2012	1275
2013	1173
2014	1147
2015	1098
2016	1105
2017	1132
2018	1095
2019	1041
2020	1010
2021	982
2022	953