Year	Number of
1986	0
1987	0
1991	0.3208
1992	0.5933
1993	0.6962
1994	0.6639
1995	1.348
1996	1.506
1997	1.346
1998	1.441
1999	1.534
2000	1.867
2001	3.075
2002	4.734
2003	3.417
2004	2.41
2005	1.786
2006	1.466
2007	1.184
2008	1.087
2009	1.073
2010	0.6985
2011	0.5743