Year Number of 1996 0.2179 1997 0.7939 1998 0.5995 1999 0.7654 2000 0.7842 2001 0.7641 2002 0.6183 2003 0.6762 2004 0.6525 2005 0.6481 2006 0.61 2007 0.6473 2008 0.6159 2009 0.6171 2010 0.8033 2011 0.7196 2012 0.635