Year	Number
1970	17800
1971	18700
1972	19000
1973	20000
1974	22000
1975	24000
1976	26000
1977	27000
1978	27000
1979	27500
1980	27500
1981	81500
1982	93000
1983	93000
1984	100000
1985	104000
1986	122500
1987	128500
1988	135200
1989	143000
1990	145700
1991	111900
1992	115300
1993	115300
1994	115300
1995	121100
1996	126000
1997	126000
1998	125500
1999	70400
2000	73256
2001	47800
2010	273160
2011	340267.623207221
2012	247780.347691014
2013	0
2014	0
2018	26069
2019	28697
2020	17990
2021	7512