Year	Number
1960	-1050
1961	-707
1962	-546
1963	-33
1964	867
1965	1838
1966	2598
1967	3180
1968	3467
1969	3287
1970	2745
1971	1975
1972	-73
1973	-3042
1974	-6917
1975	-12089
1976	-16280
1977	-20250
1978	-23556
1979	-26115
1980	-28047
1981	-29449
1982	-30588
1983	-31183
1984	-31894
1985	-32050
1986	-32117
1987	-31768
1988	-31346
1989	-30574
1990	-29479
1991	-28324
1992	-27139
1993	-25843
1994	-24238
1995	-22495
1996	-20330
1997	-18375
1998	-16403
1999	-14046
2000	-11295
2001	-8623
2002	-6134
2003	-4527
2004	-4156
2005	-3832
2006	-3980
2007	-4748
2008	-5674
2009	-6997
2010	-8686
2011	-11262
2012	-13770
2013	-15243
2014	-15527
2015	-15356
2016	-14947
2017	-13560
2018	-12115
2019	-11439
2020	-9902
2021	-8716
2022	-4800
2023	-4800