Year	Number
1960	2011
1961	2115
1962	2233
1963	2369
1964	2524
1965	2694
1966	2871
1967	3050
1968	3237
1969	3462
1970	3725
1971	4011
1972	4331
1973	4687
1974	5099
1975	5602
1976	6202
1977	6898
1978	7647
1979	8376
1980	9030
1981	9587
1982	10052
1983	10491
1984	10996
1985	11635
1986	12427
1987	13356
1988	14358
1989	15637
1990	17456
1991	19163
1992	19174
1993	18987
1994	19535
1995	19911
1996	20553
1997	21312
1998	22123
1999	22945
2000	23784
2001	24658
2002	25574
2003	26482
2004	27379
2005	28309
2006	29308
2007	30378
2008	31506
2009	32731
2010	34059
2011	35455
2012	36926
2013	38497
2014	40142
2015	41731
2016	43167
2017	44523
2018	45895
2019	47309
2020	48594
2021	49700
2022	50841
2023	52204