Year	Number
1971	43966
1972	51598
1973	58932
1974	71815
1979	113327
1980	140547
1981	185904
1982	134578
1983	124858
1984	163679
1985	144612
1986	170165
1987	169564
1988	145538
1989	166674
1990	155257
1991	166812
1992	196099
1998	247374
1999	242284
2000	284724
2001	337155
2002	366729
2003	360986
2006	339172
2007	358609
2008	393699
2009	408364
2010	487529
2011	484717
2016	1746550