Year	Number
1960	-5671
1961	-8392
1962	-8903
1963	-8682
1964	-8341
1965	-8077
1966	-7838
1967	-7991
1968	-8478
1969	-8200
1970	-8751
1971	-7499
1972	-7346
1973	-7524
1974	-7683
1975	-7768
1976	-7895
1977	-8154
1978	-8397
1979	-9106
1980	-10709
1981	-12086
1982	-12529
1983	-12544
1984	-12413
1985	-8051
1986	-8620
1987	-9002
1988	-9023
1989	-8588
1990	-7878
1991	-7149
1992	-6650
1993	-6554
1994	-6615
1995	-6723
1996	-6827
1997	-6865
1998	-6730
1999	-6103
2000	-5185
2001	-4252
2002	-3613
2003	-3472
2004	-3504
2005	-3595
2006	-3684
2007	-3731
2008	-3624
2009	-3056
2010	-2230
2011	-1410
2012	-880
2013	-796
2014	-799
2015	-583
2016	-103
2017	1446
2018	35502
2019	-19248
2020	2370
2021	2632
2022	-800
2023	-800