Year	Number
1960	14429
1961	14661
1962	14809
1963	14936
1964	14971
1965	14947
1966	14950
1967	14970
1968	15023
1969	15126
1970	15332
1971	15559
1972	15696
1973	15794
1974	15904
1975	16057
1976	16254
1977	16483
1978	16732
1979	16982
1980	17227
1981	17465
1982	17692
1983	17914
1984	18136
1985	18293
1986	18379
1987	18451
1988	18508
1989	18548
1990	18595
1991	18860
1992	19315
1993	19733
1994	20135
1995	20552
1996	20973
1997	21396
1998	21830
1999	22268
2000	22694
2001	23112
2002	23542
2003	23982
2004	24447
2005	24959
2006	25498
2007	26062
2008	26644
2009	27220
2010	27795
2011	28373
2012	28928
2013	29423
2014	29840
2015	30224
2016	30557
2017	30821
2018	31070
2019	31298
2020	31494
2021	31666
2022	31821
2023	31985