Year	Number
1960	19660
1961	20125
1962	20579
1963	21040
1964	21508
1965	21986
1966	22476
1967	22981
1968	23497
1969	24034
1970	24646
1971	25317
1972	25996
1973	26679
1974	27367
1975	28097
1976	28883
1977	29689
1978	30521
1979	31381
1980	32281
1981	33222
1982	34182
1983	35146
1984	36109
1985	37068
1986	38023
1987	38966
1988	39898
1989	40818
1990	41764
1991	42663
1992	43002
1993	43341
1994	43610
1995	43823
1996	43981
1997	44096
1998	44183
1999	44266
2000	44300
2001	44120
2002	42600
2003	41114
2004	39636
2005	38179
2006	36737
2007	35319
2008	33936
2009	32602
2010	31538
2011	31761
2012	31941
2013	32118
2014	32307
2015	32517
2016	32739
2017	32974
2018	33226
2019	33491
2020	33770
2021	34026
2022	34263
2023	34558