Year	Number
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	-282
1974	-2219
1975	9542
1976	9663
1977	10652
1978	10971
1979	8925
1980	5453
1981	-607
1982	-159
1983	569
1984	694
1985	2122
1986	2698
1987	3190
1988	4162
1989	1355
1990	399
1991	-7212
1992	-7769
1993	-7759
1994	-7986
1995	-7916
1996	-8429
1997	-8625
1998	-8572
1999	-8157
2000	-12665
2001	-9894
2002	-9937
2003	-9731
2004	-5797
2005	-1481
2006	-1590
2007	-1970
2008	-3235
2009	-4019
2010	-1607
2011	-309
2012	-769
2013	-1580
2014	-1586
2015	-5529
2016	-5475
2017	-5412
2018	-5352
2019	-5265
2020	-3506
2021	-1997
2022	-5000
2023	-5000