Year	Number
1960	11861
1961	12121
1962	12409
1963	12733
1964	13100
1965	13491
1966	13705
1967	13719
1968	13711
1969	13863
1970	14170
1971	14469
1972	14767
1973	15080
1974	15329
1975	15484
1976	15608
1977	15702
1978	15797
1979	16100
1980	16588
1981	17067
1982	17532
1983	17966
1984	18367
1985	18756
1986	19134
1987	19497
1988	19858
1989	20217
1990	20547
1991	20815
1992	21029
1993	21225
1994	21457
1995	21739
1996	22087
1997	22510
1998	22977
1999	23480
2000	24053
2001	24664
2002	25343
2003	26104
2004	26859
2005	27571
2006	28306
2007	29085
2008	29848
2009	30615
2010	31365
2011	32036
2012	32624
2013	33175
2014	33686
2015	34173
2016	34639
2017	35067
2018	35467
2019	35893
2020	36456
2021	37147
2022	37869
2023	38618