Year	Number
1960	21767
1961	24618
1962	27413
1963	28891
1964	29541
1965	30575
1966	32383
1967	34180
1968	35399
1969	33145
1970	26616
1971	22182
1972	21986
1973	22835
1974	25395
1975	30911
1976	36049
1977	38225
1978	39158
1979	37375
1980	32491
1981	29606
1982	30433
1983	31756
1984	17021
1985	25773
1986	27190
1987	31242
1988	31455
1989	34644
1990	-1196051
1991	460628
1992	52620
1993	-44820
1994	-42817
1995	1693
1996	20602
1997	20792
1998	20819
1999	20438
2000	19193
2001	17088
2002	14550
2003	11232
2004	7427
2005	68878
2006	96486
2007	94844
2008	93141
2009	90945
2010	94736
2011	191544
2012	191164
2013	190228
2014	-84910
2015	259114
2016	-90785
2017	140685
2018	144967
2019	9088
2020	-254177
2021	-36843
2022	11999
2023	11999