Year	Number of
1988	0.749
1993	2.228
1996	4.163
1999	4.004
2001	1.299
2002	0.7416
2003	0.5497
2004	1.007
2005	0.3149
2006	0.2422
2007	0.1279
2008	0
2009	0.04257