Year	Number
1960	16472
1961	16834
1962	17221
1963	17625
1964	18058
1965	18500
1966	18957
1967	19467
1968	20011
1969	20558
1970	21089
1971	21517
1972	21873
1973	22251
1974	22638
1975	23030
1976	23416
1977	23803
1978	24205
1979	24616
1980	25003
1981	25346
1982	25689
1983	26055
1984	26420
1985	26785
1986	27159
1987	27542
1988	27944
1989	28357
1990	28765
1991	29168
1992	29581
1993	30012
1994	30447
1995	30890
1996	31337
1997	31770
1998	32190
1999	32615
2000	33026
2001	33376
2002	33693
2003	34000
2004	34300
2005	34603
2006	34889
2007	35150
2008	35401
2009	35675
2010	35926
2011	36189
2012	36505
2013	36806
2014	37096
2015	37355
2016	37609
2017	37889
2018	38181
2019	38482
2020	38756
2021	39039
2022	39327
2023	39584