Year	Number
1970	20400
1971	20400
1972	20400
1973	20400
1974	20400
1975	22800
1976	26400
1977	26500
1978	29200
1979	29100
1980	31080
1981	32240
1982	39720
1983	36275
1984	38803
1985	41986
1986	48433
1987	53891
1988	58400
1989	61853
1990	69872
1991	78161
1992	76806
1993	76180
1994	78836
1995	83707
1996	89463
1997	98125
1998	105869
1999	111184
2000	114347
2001	123302
2002	126556
2003	131856
2004	139936
2005	133074
2006	131564
2007	132854
2008	132756
2009	128964
2010	129314
2011	132995
2012	135000
2013	136000
2014	125658
2015	120925
2016	121088
2017	113852
2018	113455
2019	91129
2020	91000
2021	85705
2022	86484
