Year	Number
1960	-10787
1961	-12138
1962	-12116
1963	-12167
1964	-13919
1965	-14060
1966	-14569
1967	-14406
1968	-14147
1969	-14971
1970	-17223
1971	-19180
1972	-33274
1973	-34254
1974	-34541
1975	-33173
1976	-32897
1977	-33079
1978	-34373
1979	-36786
1980	-32766
1981	-33719
1982	-34781
1983	-35457
1984	-35794
1985	-36002
1986	-37476
1987	-39866
1988	-37284
1989	-37882
1990	-39640
1991	-28138
1992	-24497
1993	-25689
1994	-20570
1995	-16351
1996	-15594
1997	-14893
1998	-14279
1999	-14027
2000	-14327
2001	-13634
2002	-12668
2003	-11335
2004	-13720
2005	-14065
2006	-13119
2007	-12836
2008	-12878
2009	-12937
2010	-13748
2011	-14196
2012	-7245
2013	-7689
2014	-5417
2015	-7210
2016	-6483
2017	-5941
2018	30345
2019	-23188
2020	19
2021	-4271
2022	-3800
2023	-3800