Year	Number
1960	-1349
1961	-2025
1962	-2661
1963	-3273
1964	-4288
1965	-5611
1966	-6961
1967	-8101
1968	-8856
1969	-9523
1970	-10098
1971	-10552
1972	-10817
1973	-10842
1974	-10579
1975	-10226
1976	-10017
1977	-10183
1978	-10994
1979	-12767
1980	-15059
1981	-17221
1982	-18622
1983	-19772
1984	-20640
1985	-21225
1986	-21608
1987	-21822
1988	-21910
1989	-21784
1990	-21639
1991	-15526
1992	-13467
1993	-13075
1994	-13197
1995	-13242
1996	-13275
1997	-13282
1998	-13251
1999	-13212
2000	-13176
2001	-13060
2002	-12758
2003	-12523
2004	-12657
2005	-13000
2006	-13328
2007	-13629
2008	-13886
2009	-14130
2010	-14327
2011	-14512
2012	-7152
2013	-6912
2014	-6715
2015	-6524
2016	-6311
2017	-6110
2018	30080
2019	-24678
2020	802
2021	-4316
2022	-3900
2023	-3900