Year Number 1996 1.03555142879486 1998 0.3500617146492 2000 1.22359979152679 2002 0.36293163895607 2003 1.16978526115417 2004 1.2183393239975 2005 1.00011491775513 2006 0.860106229782104 2007 0.617986261844635 2008 0.640764355659485 2009 0.685753643512726 2010 0.790275514125824 2011 0.849078357219696 2012 0.893705666065216 2013 0.85335773229599 2014 0.816450417041779 2015 0.837734758853912 2016 0.998592257499695 2017 0.974609792232513 2018 0.993263125419617 2019 0.906494319438934 2020 0.864660143852234 2021 0.831884622573853 2022 0.869225919246674