Year	Number
1960	2561
1961	2620
1962	2692
1963	2776
1964	2861
1965	2949
1966	3046
1967	3147
1968	3255
1969	3372
1970	3498
1971	3633
1972	3778
1973	3934
1974	4100
1975	4275
1976	4463
1977	4661
1978	4870
1979	5093
1980	5327
1981	5572
1982	5831
1983	6102
1984	6389
1985	6698
1986	7024
1987	7367
1988	7731
1989	8115
1990	8504
1991	8841
1992	8711
1993	8533
1994	8764
1995	9109
1996	9539
1997	9984
1998	10469
1999	11160
2000	12035
2001	12917
2002	13794
2003	14657
2004	15479
2005	16141
2006	16604
2007	17011
2008	17450
2009	17926
2010	18438
2011	18975
2012	19528
2013	20099
2014	20697
2015	21342
2016	22033
2017	22444
2018	22606
2019	22863
2020	23218
2021	23656
2022	24164
2023	24720