Year	Number of
1990	0.04462
1995	0.5522
1998	0.4925
1999	0.49
2001	0.4418
2002	0.6975
2003	0.4438
2004	0.3233
2005	0.3602
2006	0.5233
2007	0.4569
2008	0.2694
2009	0.3618
2010	0.3437
2011	0.2912
2012	0.2026