Year Number 1996 0.328688681125641 1998 0.250788927078247 2000 0.360480934381485 2002 0.791833281517029 2003 0.374170809984207 2004 0.436752140522003 2005 0.383150041103363 2006 0.188148677349091 2007 0.175549507141113 2008 0.181815281510353 2009 0.180615961551666 2010 0.179316192865372 2011 0.209991171956062 2012 0.366530209779739 2013 0.42616268992424 2014 0.273521840572357 2015 0.107048586010933 2016 -0.0476647540926933 2017 -0.17114095389843 2018 -0.176231503486633 2019 -0.0380972623825073 2020 -0.0935939401388168 2021 0.144544184207916 2022 0.139385640621185