Year	Number
1960	4371
1961	11045
1962	12553
1963	10462
1964	9679
1965	9382
1966	9493
1967	-2018
1968	-11506
1969	-5097
1970	4590
1971	7629
1972	18032
1973	28061
1974	27542
1975	12858
1976	-9194
1977	-22440
1978	-28581
1979	-26852
1980	-15213
1981	-7668
1982	7831
1983	11546
1984	-963
1985	-13674
1986	-10282
1987	-7835
1988	-16784
1989	-9077
1990	71491
1991	30577
1992	6535
1993	12337
1994	20272
1995	26133
1996	24974
1997	11761
1998	-1765
1999	-8993
2000	-6080
2001	17140
2002	47693
2003	42181
2004	24480
2005	19148
2006	14521
2007	2976
2008	4679
2009	12403
2010	6258
2011	-2405
2012	-1539
2013	22547
2014	48532
2015	47165
2016	50012
2017	48815
2018	80419
2019	103392
2020	38220
2021	38220
2022	12999
2023	12999