Year	Number
1960	22356
1961	101265
1962	82788
1963	58568
1964	21798
1965	-1040
1966	15252
1967	27789
1968	25724
1969	20746
1970	-18454
1971	2310
1972	19443
1973	7986
1974	1724
1975	-58461
1976	-54583
1977	-22798
1978	-6720
1979	4068
1980	17242
1981	24245
1982	21668
1983	5457
1984	12108
1985	14005
1986	22923
1987	26589
1988	34171
1989	34078
1990	58538
1991	69110
1992	41548
1993	40015
1994	29901
1995	24956
1996	-361
1997	-2284
1998	10962
1999	25428
2000	24066
2001	35173
2002	48658
2003	41871
2004	38681
2005	32421
2006	36928
2007	71939
2008	94153
2009	69106
2010	75604
2011	66975
2012	67464
2013	83892
2014	77880
2015	71488
2016	70637
2017	45208
2018	40899
2019	43546
2020	53786
2021	23872
2022	39998
2023	39998