Year	Number
1960	13502
1961	15301
1962	17331
1963	19629
1964	22242
1965	25217
1966	28546
1967	31661
1968	35076
1969	38827
1970	42980
1971	47575
1972	52661
1973	58257
1974	64464
1975	71355
1976	79013
1977	83920
1978	88534
1979	93448
1980	98631
1981	103671
1982	108971
1983	114930
1984	121217
1985	128300
1986	136107
1987	144314
1988	154200
1989	163563
1990	172527
1991	183343
1992	194451
1993	204363
1994	208458
1995	212513
1996	221218
1997	228671
1998	230674
1999	232361
2000	233778
2001	234887
2002	235644
2003	236069
2004	236237
2005	236222
2006	236132
2007	236628
2008	240262
2009	243744
2010	247262
2011	250919
2012	253954
2013	257202
2014	260626
2015	264207
2016	268025
2017	272016
2018	276170
2019	280485
2020	285376
2021	290545
2022	295322
2023	300163