Year Number 1996 0.830568552017212 1998 0.856274604797363 2000 0.301403164863586 2002 0.473941057920456 2003 0.45265343785286 2004 0.389960020780563 2005 0.386921286582947 2006 -0.0340580493211746 2007 0.0618767961859703 2008 -0.0669486746191978 2009 -0.272885650396347 2010 -0.190827518701553 2011 -0.0712881982326508 2012 -0.0677748322486877 2013 -0.0510276891291142 2014 0.553164601325989 2015 0.569660663604736 2016 0.897029459476471 2017 0.586045205593109 2018 0.833207309246063 2019 0.779773771762848 2020 0.661915123462677 2021 0.724108815193176 2022 0.764339506626129