Year	Number
1970	14900
1971	16500
1972	18400
1973	20900
1974	20000
1975	21000
1976	23100
1977	24000
1978	25800
1979	26100
1980	27200
1981	27800
1982	36400
1983	37700
1984	38000
1985	37800
1986	37700
1987	38700
1988	40100
1989	39900
1990	42000
1991	47400
1992	63600
1993	73000
1994	87700
1995	109000
1996	118100
1997	121300
1998	127900
1999	127200
2000	138700
2001	133561
2002	135516
2003	128449
2004	137049
2005	141968
2006	149512
2007	151070
2008	150738
2009	138942
2010	176195
2011	166729.997287091
2012	162715.735981131
2013	166251
2014	162576
2015	152056
2016	149030
2017	156761
2018	130260
2019	330226
2020	121668
2021	161093