Year	Number
1960	19370
1961	20511
1962	21599
1963	22667
1964	23693
1965	24663
1966	25569
1967	26416
1968	27220
1969	27995
1970	28760
1971	29530
1972	30283
1973	30953
1974	31511
1975	31983
1976	32401
1977	32828
1978	33324
1979	33922
1980	34616
1981	35411
1982	36343
1983	37342
1984	38344
1985	39374
1986	40459
1987	41630
1988	42872
1989	44147
1990	45430
1991	46806
1992	48326
1993	49790
1994	51041
1995	52070
1996	52829
1997	53263
1998	53405
1999	53371
2000	53231
2001	52993
2002	52690
2003	52355
2004	51982
2005	51586
2006	51196
2007	50811
2008	50425
2009	50058
2010	49732
2011	49520
2012	49465
2013	49484
2014	49452
2015	49327
2016	49170
2017	48963
2018	48697
2019	48432
2020	48179
2021	47928
2022	47675
2023	47393