Year	Number of
1980	4.161
1988	3.422
1989	2.639
1991	2.778
1992	2.177
1996	4.841
1999	6.348
2000	7.122
2001	7.244
2002	4.591
2003	4.33
2004	3.832
2005	3.399
2006	4.84
2007	3.934
2008	3.838
2009	3.325
2010	2.866
2011	2.33
2012	2.686