Year	Number
1960	-725
1961	-717
1962	-424
1963	88
1964	351
1965	369
1966	387
1967	399
1968	442
1969	477
1970	556
1971	674
1972	755
1973	796
1974	818
1975	832
1976	884
1977	1001
1978	1124
1979	1169
1980	1198
1981	1209
1982	1146
1983	-588
1984	-544
1985	-520
1986	-517
1987	-544
1988	-532
1989	-791
1990	-904
1991	-925
1992	-933
1993	-944
1994	-961
1995	-919
1996	-727
1997	-487
1998	-417
1999	-455
2000	-460
2001	-431
2002	-304
2003	-130
2004	-61
2005	-93
2006	-342
2007	-1179
2008	-2190
2009	-2603
2010	-2613
2011	-2521
2012	-2639
2013	-1988
2014	-1668
2015	-1676
2016	-1687
2017	-1046
2018	-952
2019	-861
2020	-378
2021	-378
2022	-100
2023	-100