Year	Number of
1991	0.3645
1993	0.6206
1997	1.355
1999	1.941
2000	2.283
2001	1.849
2002	1.944
2004	1.074
2005	1.713
2006	1.509
2007	1.18
2008	1.031
2009	1.066
2011	0.7196
2012	0.8376