Year	Number
1960	-25396
1961	-33163
1962	-39116
1963	-41979
1964	-44406
1965	-46683
1966	-48509
1967	-49556
1968	-49387
1969	-47446
1970	-44466
1971	-50012
1972	-61788
1973	-64655
1974	-62793
1975	-57074
1976	-51223
1977	-46105
1978	-37588
1979	-42543
1980	-43166
1981	-22159
1982	-21055
1983	-19994
1984	-18994
1985	-18048
1986	-17146
1987	-16290
1988	-15474
1989	-14705
1990	-15438
1991	-20665
1992	-21867
1993	-24358
1994	-27272
1995	-28713
1996	-25052
1997	-34305
1998	-32396
1999	-30770
2000	-24942
2001	-22329
2002	-23874
2003	-19525
2004	-13532
2005	-11973
2006	-9462
2007	-14434
2008	-24636
2009	-30328
2010	-27718
2011	-28752
2012	-17531
2013	-15301
2014	-14543
2015	-14372
2016	-14454
2017	-14498
2018	-14219
2019	-13686
2020	-7068
2021	-7068
2022	-6000
2023	-6000