Year	Number
1960	13410
1961	12194
1962	10889
1963	3064
1964	3822
1965	4822
1966	5117
1967	4572
1968	3087
1969	1596
1970	2151
1971	2874
1972	3589
1973	4610
1974	5246
1975	5435
1976	5249
1977	3855
1978	2706
1979	-1800
1980	-1493
1981	-1561
1982	-1894
1983	-2113
1984	-1822
1985	-793
1986	997
1987	808
1988	591
1989	-9590
1990	-11026
1991	-10556
1992	-9002
1993	-7672
1994	-8114
1995	-8617
1996	-8034
1997	-8257
1998	-8915
1999	-8519
2000	-10833
2001	-9448
2002	-8311
2003	-7755
2004	-8142
2005	-8663
2006	-10827
2007	-11805
2008	-11683
2009	-9646
2010	-8592
2011	-1248
2012	-2156
2013	-1527
2014	813
2015	3932
2016	7470
2017	10802
2018	11426
2019	10664
2020	0
2021	0
2022	-850
2023	-850