Year	Number
1974	4700
1975	5400
1976	6200
1977	6300
1978	7200
1979	8300
1980	9500
1981	10000
1982	8700
1983	9500
1984	10100
1985	10500
1986	12200
1987	12800
1988	15100
1989	16000
1990	18800
1991	19400
1992	26300
1993	30100
1994	34000
1995	34200
1996	38000
1997	39000
1998	41100
1999	44400
2000	48330
2001	50783
2002	54952
2003	71224
2004	87217
2009	170588
2010	240855.107016004
2011	269521
2012	311758
2013	327076
2014	352224
2015	437638
2016	463947
2017	459137
2018	455956
2019	426157.272
2020	185260
2021	234612