Year	Number
1960	13130
1961	13457
1962	13874
1963	14325
1964	14714
1965	14984
1966	15107
1967	15075
1968	14969
1969	14903
1970	14983
1971	15252
1972	15692
1973	16250
1974	16842
1975	17419
1976	17968
1977	18514
1978	19042
1979	19525
1980	19930
1981	20185
1982	20232
1983	20098
1984	19929
1985	19843
1986	19806
1987	19785
1988	19768
1989	19756
1990	19778
1991	19925
1992	20326
1993	21014
1994	21864
1995	22738
1996	23539
1997	24222
1998	24815
1999	25493
2000	26384
2001	27537
2002	28667
2003	29800
2004	30831
2005	31688
2006	32297
2007	32644
2008	32839
2009	32914
2010	32814
2011	32842
2012	33278
2013	33866
2014	34604
2015	35590
2016	36547
2017	37512
2018	38626
2019	39776
2020	40713
2021	41297
2022	41866
2023	42757