Year	Number
1960	-10446
1961	-8340
1962	-7589
1963	-8107
1964	-10677
1965	-13158
1966	-20869
1967	-22724
1968	-25763
1969	-26779
1970	-25428
1971	-33070
1972	-28251
1973	-25703
1974	-22142
1975	-15218
1976	-13508
1977	6675
1978	5914
1979	4349
1980	6622
1981	-1768
1982	-716
1983	9184
1984	24296
1985	50994
1986	72169
1987	92834
1988	101477
1989	98199
1990	94487
1991	81545
1992	88349
1993	88952
1994	100207
1995	94297
1996	102218
1997	113370
1998	119482
1999	124435
2000	174011
2001	198361
2002	224999
2003	226003
2004	244359
2005	245376
2006	251101
2007	247032
2008	217538
2009	194571
2010	114491
2011	115314
2012	113421
2013	102150
2014	94785
2015	80603
2016	97737
2017	78257
2018	60604
2019	60824
2020	57483
2021	46165
2022	48997
2023	48997