Year	Number
1960	3078
1961	3319
1962	3567
1963	3817
1964	4065
1965	4320
1966	4595
1967	4902
1968	5248
1969	5629
1970	6047
1971	6498
1972	6976
1973	7483
1974	8010
1975	8548
1976	9097
1977	9654
1978	10206
1979	10748
1980	11294
1981	11857
1982	12488
1983	13179
1984	13874
1985	14573
1986	15271
1987	15975
1988	16678
1989	17375
1990	18062
1991	18780
1992	19529
1993	20264
1994	20983
1995	21683
1996	22122
1997	22298
1998	22449
1999	22590
2000	22730
2001	23334
2002	24414
2003	25500
2004	26590
2005	27672
2006	27886
2007	27262
2008	26670
2009	26072
2010	25488
2011	25225
2012	25255
2013	25291
2014	25343
2015	25375
2016	25617
2017	26080
2018	26525
2019	26950
2020	27326
2021	27679
2022	27862
2023	27883