Year	Number
1960	-10246
1961	7117
1962	4013
1963	4388
1964	4302
1965	4063
1966	3972
1967	4086
1968	4102
1969	4144
1970	4673
1971	5844
1972	10820
1973	11901
1974	13006
1975	14294
1976	15468
1977	16585
1978	17662
1979	18242
1980	9690
1981	1920
1982	-1274
1983	188
1984	964
1985	1869
1986	2073
1987	-521
1988	1950
1989	2982
1990	-651
1991	-62389
1992	7805
1993	9203
1994	7520
1995	7879
1996	7573
1997	5364
1998	3799
1999	3950
2000	2082
2001	-5
2002	1543
2003	511
2004	480
2005	351
2006	185
2007	117
2008	98
2009	46
2010	-20
2011	28
2012	3968
2013	7198
2014	8072
2015	7368
2016	5901
2017	4465
2018	3346
2019	489
2020	243
2021	243
2022	-9999
2023	-9999