Year Number 1996 -0.308270066976547 1998 -0.064743272960186 2000 -0.452023267745972 2002 -0.72901463508606 2003 -0.723995983600616 2004 -0.699335694313049 2005 -0.777636587619781 2006 -1.09882938861847 2007 -1.13693797588348 2008 -1.12754857540131 2009 -1.25917947292328 2010 -1.12405169010162 2011 -0.956343531608582 2012 -0.943592429161072 2013 -0.837611019611359 2014 -0.920283794403076 2015 -1.14157736301422 2016 -0.958474397659302 2017 -1.02322399616241 2018 -0.886888802051544 2019 -0.796693980693817 2020 -0.871133387088776 2021 -0.719614744186401 2022 -0.45972153544426