Year	Number
1980	149882
1981	116008
1982	107044
1983	114714
1984	140079
1985	106488
1986	229661
1987	236276
1988	193753
1989	223595
1990	247992
1991	234920
1992	239974
1993	272001
1994	272163
1995	293195
1996	303952
1997	337660
1998	320609
1999	334857
2000	417144
2001	352739
2002	355940
2003	390787
2004	400637
2005	442149
2006	449051
2007	472248
2008	493580
2009	462716
2010	523261
2011	496558
2012	495530
2013	517617
2014	522998
2015	534907
2016	557853
2017	612757