Year	Number
1960	5690
1961	5747
1962	5871
1963	6016
1964	6163
1965	6309
1966	6433
1967	6576
1968	6760
1969	6954
1970	7156
1971	7398
1972	7563
1973	7724
1974	8025
1975	8280
1976	8481
1977	8635
1978	8679
1979	8726
1980	8790
1981	8879
1982	9050
1983	9226
1984	9413
1985	9615
1986	9771
1987	9858
1988	9876
1989	9885
1990	9949
1991	10066
1992	10244
1993	10523
1994	10848
1995	11232
1996	11710
1997	12192
1998	12455
1999	12514
2000	12488
2001	12413
2002	12679
2003	13126
2004	13532
2005	14088
2006	14715
2007	15331
2008	15910
2009	16462
2010	17191
2011	17997
2012	18679
2013	19420
2014	20254
2015	21131
2016	22003
2017	22747
2018	21815
2019	21347
2020	22075
2021	22213
2022	22424
2023	22719