Year	Number
1960	15000
1961	15000
1962	15000
1963	15000
1964	15000
1965	17100
1966	17100
1967	17100
1968	17100
1969	17100
1970	23200
1971	23200
1972	23200
1973	23200
1974	23200
1975	28400
1976	28200
1977	29500
1978	30000
1979	30698
1980	32659
1981	34927
1982	36330
1983	37493
1984	41819
1985	43772
1986	47164
1987	50919
1988	58492
1989	65750
1990	65057
1991	68935
1992	75880
1993	77966
1994	79786
1995	76769
1996	77935
1997	77377
1998	77700
1999	83084
2000	83326
2001	85662
2002	87674
2003	88426
2004	91719
2005	94665
2006	93427
2007	91789
2008	90600
2009	90341
2010	118388
2011	85727
2012	82542
2013	115762
2014	114420
2015	116165
2016	101407
2017	101444
2018	100444
2019	96719
2020	71844
2021	65913
2022	96284