Year	Number
1960	-830
1961	-773
1962	-700
1963	-640
1964	-618
1965	-809
1966	-1592
1967	-2636
1968	-3189
1969	-3383
1970	-3603
1971	-3822
1972	-4032
1973	-4239
1974	-4466
1975	-4367
1976	-3331
1977	-1931
1978	-1405
1979	-1444
1980	-1440
1981	-1425
1982	-1405
1983	-1398
1984	-1394
1985	-2003
1986	-4565
1987	-7923
1988	-9608
1989	-10129
1990	-10612
1991	-16491
1992	-14646
1993	-14927
1994	-15170
1995	-14575
1996	-9085
1997	-6530
1998	-5711
1999	-5926
2000	-6081
2001	-6207
2002	-6349
2003	-6513
2004	-6639
2005	-6729
2006	-7016
2007	-8101
2008	-9625
2009	-10445
2010	-10666
2011	-10836
2012	-10945
2013	-11000
2014	-11023
2015	-11047
2016	-11139
2017	-11605
2018	-11738
2019	-11865
2020	-6003
2021	-6003
2022	-3557
2023	-3289