Year	Number
1960	2060
1961	703
1962	-624
1963	-1707
1964	-2620
1965	-3544
1966	-4604
1967	-5937
1968	-8028
1969	-11148
1970	-12730
1971	-13287
1972	-13818
1973	-14314
1974	-14518
1975	-14348
1976	-14094
1977	-14289
1978	-14606
1979	-14558
1980	-14254
1981	-13572
1982	-12126
1983	-10672
1984	-9735
1985	-8838
1986	-8050
1987	-6833
1988	-6585
1989	-7236
1990	-7498
1991	-7720
1992	-7856
1993	-7917
1994	-7951
1995	-8333
1996	-7396
1997	-6937
1998	-7043
1999	-7439
2000	-11074
2001	-14628
2002	-16958
2003	-17099
2004	-15661
2005	-16092
2006	-13159
2007	-10752
2008	-9460
2009	-8510
2010	-7696
2011	-6982
2012	-6318
2013	-5655
2014	-4914
2015	-4156
2016	-3506
2017	-3090
2018	-2963
2019	-2902
2020	-1486
2021	-1486
2022	-1500
2023	-1500