Year	Number
1971	48468
1972	53657
1973	57406
1974	62015
1975	65113
1976	69061
1977	79961
1978	81700
1979	83252
1980	81926
1981	79534
1982	77779
1983	77838
1984	74795
1985	72551
1986	70681
1987	71922
1988	74717
1989	78776
1990	79229
1992	86024
1996	95932
1997	97405
1998	101517
1999	104070
2000	105432
2001	107846
2002	111766
2003	118234
2004	122556
2005	129438
2006	128925
2007	130463
2008	129257
2009	128680
2010	127002
2011	126864
2012	127123
2013	129179
2014	133001
2015	129008
2016	128761
2017	125270
2018	122424
2019	122055
2020	114124
