Year	Number
1970	25700
1971	29800
1972	31400
1973	33000
1974	35000
1975	35000
1976	38000
1977	34000
1978	36000
1979	36500
1980	90000
1981	115800
1982	99300
1983	117200
1984	130000
1985	99800
1986	122000
1987	128400
1988	104700
1989	89200
1990	87600
1991	46100
2010	163812.745808619
2011	177005.4
2012	178709.7
2013	258336
2014	251652
2016	4486
2017	4486
2018	33728.9686579889
2019	34065.5568461863