Year	Number
1960	12482
1961	13657
1962	14902
1963	16186
1964	17426
1965	18587
1966	19669
1967	20652
1968	21558
1969	20809
1970	18405
1971	17001
1972	17891
1973	18816
1974	19704
1975	20630
1976	21268
1977	23743
1978	23435
1979	-8680
1980	-22177
1981	-23113
1982	-23315
1983	-23399
1984	-32741
1985	-34757
1986	-35994
1987	-35349
1988	-25623
1989	98512
1990	2119
1991	5419
1992	-196273
1993	-126968
1994	-112567
1995	-50217
1996	-51023
1997	-51638
1998	-52266
1999	-52843
2000	-51873
2001	-44486
2002	-34971
2003	-30238
2004	-30623
2005	-31023
2006	-31302
2007	-31530
2008	-31822
2009	-32000
2010	-31991
2011	-29214
2012	-28731
2013	-28257
2014	-27763
2015	-27283
2016	-26804
2017	-26326
2018	-25835
2019	-25363
2020	-12825
2021	-12825
2022	-5000
2023	-5000