Year	Number
1970	28700
1971	32000
1972	34700
1973	36700
1974	30600
1975	27200
1976	32000
1977	33400
1978	30400
1979	31400
1980	18900
1981	25300
1982	24000
1983	24600
1984	28400
1985	31600
1986	31700
1987	32900
1988	36800
1989	38300
1990	44200
1991	38600
1992	58600
1993	70500
1994	75100
1995	78500
1996	84900
1997	92800
1998	103900
1999	111400
2000	119945
2001	111342
2002	105996
2003	104377
2004	121815
2005	145952
2006	177088
2007	197132
2008	215275
2009	271835
2010	369174
2011	420222
2012	476115
2013	568212.396628194
2014	628104
2015	706067
2016	743673
2017	742260
2018	772925.545
2019	742503
2020	364856.074
2021	534041.09