Year	Number
1971	415016
1972	436229
1973	448852
1974	460884
1975	469979
1976	517194
1977	536236
1978	549335
1979	556250
1980	560008
1981	567755
1982	583983
1983	604022
1984	633966
1985	623376
1986	816229
1987	813187
1988	781814
1989	756451
1990	739247
1991	718077
1992	704176
1993	701413
1994	753514
1995	731753
1996	710118
1997	583901
1998	432008
1999	456479
2000	464948
2001	487832
2002	477072
2003	489444
2004	724593
2005	725638
2006	656904
2007	671319
2008	684821
2009	690076
2010	698116
2011	748850
2012	747119
2015	597246
2016	584430
2017	618788