Year	Number
1960	6383
1961	6614
1962	6873
1963	7121
1964	7281
1965	7418
1966	7558
1967	7687
1968	7867
1969	8084
1970	8279
1971	8432
1972	8567
1973	8695
1974	8859
1975	9079
1976	9297
1977	9490
1978	9714
1979	9924
1980	10088
1981	10232
1982	10389
1983	10549
1984	10705
1985	10909
1986	11190
1987	11439
1988	11627
1989	11840
1990	12086
1991	12315
1992	12564
1993	12872
1994	13177
1995	13486
1996	13775
1997	14036
1998	14247
1999	14428
2000	14651
2001	14872
2002	15086
2003	15316
2004	15537
2005	15741
2006	15988
2007	16335
2008	16740
2009	17193
2010	17718
2011	18322
2012	19041
2013	19771
2014	20506
2015	21345
2016	22110
2017	22865
2018	23759
2019	24674
2020	25595
2021	26692
2022	28173
2023	29868