Year Number 1996 -0.517743170261383 1998 -0.492162376642227 2000 -0.066172294318676 2002 -0.0931836739182472 2003 -0.368299216032028 2004 -0.341314166784287 2005 -0.339232921600342 2006 -0.267819613218308 2007 -0.120370902121067 2008 -0.222542554140091 2009 -0.305793792009354 2010 -0.499709248542786 2011 -0.269735813140869 2012 -0.348777562379837 2013 -0.249215871095657 2014 -0.0407801233232021 2015 -0.092195525765419 2016 -0.0954835712909698 2017 -0.0538232065737247 2018 -0.950931131839752 2019 -0.992481052875519 2020 -0.58572518825531 2021 -0.47199821472168 2022 -0.34842848777771