Year	Number
1980	151236
1981	116938
1982	107816
1983	115127
1984	141203
1985	107706
1986	230074
1987	236645
1988	194813
1989	226263
1990	250325
1991	237662
1992	243490
1993	274493
1994	275026
1995	297307
1996	307768
1997	337660
1998	320609
1999	340171
2000	421039
2001	356817
2002	360249
2003	394169
2004	404301
2005	445623
2006	452693
2007	475860
2008	497210
2009	465541
2010	525194
2011	501866
2012	502638
2013	523638
2014	530054
2015	542600
2016	565590
2017	618617