Year Number 1996 -0.442145347595215 1998 -0.395977348089218 2000 -0.420464307069778 2002 -0.660840332508087 2003 -0.61183363199234 2004 -0.4958216547966 2005 -0.492080003023148 2006 -0.407301127910614 2007 -0.457430690526962 2008 -0.543911099433899 2009 -0.470705568790436 2010 -0.46234917640686 2011 -0.449195504188538 2012 -0.410142123699188 2013 -0.353273868560791 2014 -0.363270282745361 2015 -0.427903473377228 2016 -0.483072638511658 2017 -0.610303103923798 2018 -0.640993356704712 2019 -0.668204069137573 2020 -0.68933516740799 2021 -0.640137732028961 2022 -0.563533365726471