Year	Number
1960	39962
1961	42203
1962	44046
1963	45969
1964	47979
1965	50071
1966	52258
1967	54539
1968	56924
1969	59406
1970	62000
1971	66547
1972	71434
1973	76665
1974	82287
1975	88321
1976	94807
1977	101750
1978	109212
1979	117220
1980	125829
1981	135043
1982	144946
1983	157801
1984	174372
1985	192631
1986	212831
1987	235150
1988	259844
1989	287053
1990	317154
1991	342078
1992	348428
1993	354878
1994	361456
1995	368157
1996	374991
1997	381932
1998	389012
1999	396224
2000	403579
2001	411049
2002	418669
2003	426430
2004	434346
2005	442386
2006	450587
2007	458939
2008	467459
2009	476112
2010	484925
2011	493901
2012	503044
2013	512356
2014	521840.00000000006
2015	531499
2016	541338
2017	551358
2018	561564
2019	568804
2020	576157
2021	583695
2022	591469
2023	599504