Year	Number
1960	3690
1961	3690
1962	3690
1963	3690
1964	3690
1965	8600
1966	8600
1967	8600
1968	8600
1969	8600
1970	17000
1971	17000
1972	17000
1973	17000
1974	17000
1975	24022
1976	26206
1977	27696
1978	30521
1979	32656
1980	37465
1981	42590
1982	47025
1983	50970
1984	51739
1985	57088
1986	61111
1987	63640
1988	66663
1989	68375
1990	72753
1991	81284
1992	83869
1993	90165
1994	103268
1995	115790
1996	129808
1997	142322
1998	170001
1999	219283
2000	263667
2001	293568
2002	324839
2003	238000
2004	257932
2005	258515
2006	270573
2007	247573
2008	356502
2009	282070
2010	283343
2011	276494
2012	276135
2013	272145
2014	242684
2015	277248
2016	289108
2017	305562
2018	302398
2019	271724
2020	263786
2021	265383
2022	263308