Year	Number
1960	-14610
1961	-14453
1962	-14271
1963	-14090
1964	-13913
1965	-13720
1966	-13539
1967	-13347
1968	-13123
1969	-12864
1970	-12579
1971	-10446
1972	-7638
1973	-4350
1974	-3480
1975	-3803
1976	-4063
1977	-4207
1978	-4063
1979	-3567
1980	-2802
1981	-2478
1982	-2726
1983	-2848
1984	-3769
1985	-3564
1986	-3460
1987	-3444
1988	-3558
1989	-4012
1990	-4689
1991	-5420
1992	-6032
1993	-6432
1994	-6996
1995	-7653
1996	-8273
1997	-8707
1998	-9279
1999	-11357
2000	-15880
2001	-27672
2002	-36917
2003	-39940
2004	-40910
2005	-42163
2006	-44565
2007	-45914
2008	-44677
2009	-40108
2010	-26173
2011	-20435
2012	-17761
2013	-17238
2014	-16990
2015	-16833
2016	-16734
2017	-16628
2018	-16470
2019	-16270
2020	-8230
2021	-8230
2022	-12499
2023	-12499