Year	Number
1960	11988
1961	12102
1962	12239
1963	12389
1964	12555
1965	12737
1966	12928
1967	13124
1968	13329
1969	13563
1970	13832
1971	14132
1972	14468
1973	14841
1974	15232
1975	15631
1976	16047
1977	16496
1978	16984
1979	17510
1980	18081
1981	18689
1982	19323
1983	19992
1984	20704
1985	21444
1986	22235
1987	23071
1988	23951
1989	24856
1990	25793
1991	24895
1992	23916
1993	25135
1994	26354
1995	28324
1996	30126
1997	30813
1998	31545
1999	32040
2000	32705
2001	34185
2002	35920
2003	37937
2004	39967
2005	41411
2006	42690
2007	44066
2008	45996
2009	47966
2010	49810
2011	51670
2012	53366
2013	54899
2014	56131
2015	56822
2016	57266
2017	57958
2018	58962
2019	60103
2020	61206
2021	62151
2022	63019
2023	64197