Year	Number
1960	6327
1961	6285
1962	6250
1963	6224
1964	6211
1965	6251
1966	6445
1967	6552
1968	6495
1969	6486
1970	6510
1971	6578
1972	6684
1973	6803
1974	6949
1975	7142
1976	7333
1977	7562
1978	7833
1979	8114
1980	8407
1981	8683
1982	8943
1983	9200
1984	9467
1985	9786
1986	10272
1987	10577
1988	10576
1989	10567
1990	10567
1991	10544
1992	10519
1993	10529
1994	10554
1995	10604
1996	10711
1997	11011
1998	11468
1999	11939
2000	12410
2001	12881
2002	13332
2003	13800
2004	14328
2005	14885
2006	15479
2007	16112
2008	16586
2009	16883
2010	17208
2011	17597
2012	18035
2013	18495
2014	18972
2015	19303
2016	19569
2017	20040
2018	20658
2019	21363
2020	22192
2021	23017
2022	23900
2023	24944