Year	Number
1980	96344
1981	75640
1982	71832
1983	76423
1984	54993
1986	175371
1987	196642
1988	147693
1989	162577
1990	183111
1991	168916
1992	156931
1993	178014
1994	173366
1995	184025
1996	185744
1998	194385
1999	206247
2000	248525
2001	217755
2002	226993
2003	260508
2004	268327
2005	295895
2006	295060
2007	304703
2008	326667
2009	306096
2010	358969
2011	328454
2012	336115
2013	351332
2014	360101
2015	383024
2016	407197
2017	459287