Year	Number
1960	-34548
1961	-30609
1962	-28393
1963	-26948
1964	-25036
1965	-23414
1966	-21781
1967	-19783
1968	-17591
1969	-15337
1970	-12530
1971	-10744
1972	-8455
1973	-7058
1974	-4800
1975	-3446
1976	-2332
1977	-1938
1978	-1429
1979	-2982
1980	-4143
1981	-4674
1982	-3631
1983	-2192
1984	-1048
1985	730
1986	1790
1987	2615
1988	3239
1989	3586
1990	4246
1991	4992
1992	4796
1993	5341
1994	5091
1995	3910
1996	2549
1997	-82
1998	-3171
1999	-7500
2000	-10419
2001	-12414
2002	-13520
2003	-13488
2004	-12943
2005	-11902
2006	-9732
2007	-6448
2008	-2728
2009	2166
2010	4892
2011	7578
2012	9425
2013	10496
2014	12222
2015	13681
2016	15258
2017	15937
2018	15731
2019	15082
2020	13589
2021	12961
2022	30308
2023	-4282