Year	Number
1960	1870
1961	1890
1962	1909
1963	1923
1964	1928
1965	1996
1966	2146
1967	2321
1968	2516
1969	2736
1970	2986
1971	3198
1972	3334
1973	3451
1974	3561
1975	3663
1976	3755
1977	3841
1978	3919
1979	3990
1980	4061
1981	4182
1982	4369
1983	4572
1984	4778
1985	4994
1986	5211
1987	5418
1988	5618
1989	5794
1990	5937
1991	6171
1992	6523
1993	6914
1994	7334
1995	7752
1996	8147
1997	8518
1998	8853
1999	9142
2000	9392
2001	9619
2002	9824
2003	10060
2004	10418
2005	10869
2006	11320
2007	11728
2008	12100
2009	12476
2010	12866
2011	13239
2012	13713
2013	15449
2014	18506
2015	20542
2016	21292
2017	21865
2018	22488
2019	23680
2020	25360
2021	27472
2022	29807
2023	32184