Year	Number
1960	18620
1961	19087
1962	19440
1963	19732
1964	20089
1965	20641
1966	21412
1967	22356
1968	23363
1969	24287
1970	24994
1971	25481
1972	25817
1973	26059
1974	26247
1975	26383
1976	26482
1977	26555
1978	26638
1979	26793
1980	27074
1981	27507
1982	28091
1983	28795
1984	29601
1985	30519
1986	31558
1987	32735
1988	34060
1989	35583
1990	37457
1991	39737
1992	42339
1993	45173
1994	48087
1995	50925
1996	53627
1997	56255
1998	58973
1999	61906
2000	65134
2001	68712
2002	72591
2003	76712
2004	81075
2005	85520
2006	93705
2007	101825
2008	106229
2009	110386
2010	114609
2011	119405
2012	123192
2013	127311
2014	133046
2015	142746
2016	153352
2017	161369
2018	170210
2019	180054
2020	189984
2021	199280
2022	207471
2023	215649