Year Number 2000 11.06834 2001 10.50801 2002 9.59985 2003 9.59429 2004 9.81359 2006 8.03379 2007 7.64564 2008 7.95459 2009 8.27385 2010 7.87943 2011 8.10114 2012 9.14039 2013 10.43564 2014 9.68626 2015 9.70213 2016 9.49098 2017 9.54301