Year	Number
1960	17481
1961	17353
1962	17157
1963	17041
1964	16989
1965	17009
1966	17126
1967	17344
1968	17648
1969	18014
1970	18472
1971	18975
1972	19455
1973	19942
1974	20446
1975	20977
1976	21556
1977	22183
1978	22841
1979	23509
1980	24155
1981	24770
1982	25301
1983	25788
1984	26352
1985	26914
1986	27473
1987	28141
1988	28884
1989	29640
1990	30392
1991	31105
1992	31796
1993	32527
1994	33297
1995	34107
1996	34949
1997	35829
1998	36755
1999	37710
2000	38669
2001	39618
2002	40642
2003	41733
2004	42815
2005	43904
2006	44997
2007	46090
2008	47180
2009	48287
2010	49437
2011	50622
2012	51647
2013	52510
2014	53417
2015	54390
2016	55443
2017	56578
2018	57769
2019	59022
2020	60729
2021	62714
2022	64623
2023	66589