Year % 2006 1.28016415707089 2007 1.16267286868485 2008 1.66567893097526 2009 3.11494720432571 2010 2.83293355859471 2011 3.34867691886338 2012 3.79788657163647 2013 4.318537467084 2014 4.24739060198863 2015 3.85093164747182 2016 3.48452664274546 2017 2.96174954064201 2018 2.26826570545996 2019 2.08706915566812 2020 2.06995809018823 2021 2.03126042204704