Year	Number
1971	382862
1972	388491
1977	423482
1978	431614
1979	439920
1980	445978
1981	447714
1982	446745
1983	451474
1984	455467
1985	455149
1986	455326
1987	456675
1988	470186
1989	486205
1991	510139
1992	520708
1993	527434
1994	530512
1995	527777
1998	533475
1999	544505
2000	548300
2001	553627
2002	584701
2003	577948
2004	576742
2005	540972
2006	517082
2007	471145
2008	418466
2009	403084
2010	498827
2011	454932
2012	458467
2013	465969
2014	460408
2015	450238
2016	370444