Year	Number
1960	18768
1961	19859
1962	20979
1963	22114
1964	23263
1965	24419
1966	25581
1967	26751
1968	27929
1969	29127
1970	30352
1971	31589
1972	32846
1973	34136
1974	35448
1975	36785
1976	38147
1977	39508
1978	40878
1979	42284
1980	43728
1981	45215
1982	46749
1983	48317
1984	49916
1985	51553
1986	53220
1987	54924
1988	56689
1989	58329
1990	60019
1991	61933
1992	64350
1993	66904
1994	69118
1995	71014
1996	72568
1997	74399
1998	76556
1999	78834
2000	81230
2001	83475
2002	85621
2003	87857
2004	90103
2005	92539
2006	95185
2007	97910
2008	103542
2009	112028
2010	120493
2011	128846
2012	137016
2013	140593
2014	139911
2015	139879
2016	140579
2017	141919
2018	143873
2019	146426
2020	148667
2021	150420
2022	152658
2023	156022