Year	Number
1960	3831
1961	3792
1962	3760
1963	3736
1964	3703
1965	3664
1966	3626
1967	3607
1968	3600
1969	3612
1970	3637
1971	3663
1972	3701
1973	3738
1974	3765
1975	3774
1976	3753
1977	4204
1978	4621
1979	4121
1980	3660
1981	3627
1982	3558
1983	3440
1984	3313
1985	3176
1986	3039
1987	2931
1988	2842
1989	2761
1990	2651
1991	2505
1992	2358
1993	2217
1994	2081
1995	1958
1996	1859
1997	1768
1998	1672
1999	1584
2000	1501
2001	1423
2002	1343
2003	1255
2004	1167
2005	1089
2006	1027
2007	980
2008	948
2009	933
2010	936
2011	949
2012	962
2013	990
2014	1095
2015	1226
2016	1264
2017	1246
2018	1226
2019	1212
2020	1203
2021	1211
2022	1231