Year	Number
1960	-182
1961	389
1962	286
1963	-223
1964	-903
1965	-1131
1966	-4300
1967	-5150
1968	-8035
1969	-11437
1970	-14756
1971	-23505
1972	-25826
1973	-29645
1974	-36100
1975	-42349
1976	-50761
1977	-46262
1978	-48307
1979	-47285
1980	-44463
1981	-47021
1982	-48740
1983	-37255
1984	-29302
1985	-28843
1986	-33216
1987	-33790
1988	-32425
1989	-32522
1990	-30399
1991	-40877
1992	-36236
1993	-36822
1994	-33463
1995	-39890
1996	-43474
1997	-43356
1998	-44059
1999	-49731
2000	-66153
2001	-59249
2002	-55245
2003	-54666
2004	-47399
2005	-49600
2006	-42071
2007	-40617
2008	-42607
2009	-43051
2010	-36072
2011	-33204
2012	-32572
2013	-35666
2014	-40409
2015	-48162
2016	-39266
2017	-48049
2018	-56884
2019	-58095
2020	-23142
2021	-29118
2022	-9128
2023	-9110