Year Number 1996 -1.40572607517242 1998 -1.3539137840271 2000 -1.57441258430481 2002 -1.74340748786926 2003 -1.26578211784363 2004 -1.16626405715942 2005 -1.54093611240387 2006 -1.7702112197876 2007 -1.87161386013031 2008 -1.99042999744415 2009 -2.04333114624023 2010 -1.97357547283173 2011 -1.93561995029449 2012 -1.95603215694427 2013 -1.77882349491119 2014 -1.98501086235046 2015 -2.1540961265564 2016 -1.97087836265564 2017 -1.65064537525177 2018 -1.80479407310486 2019 -1.88934803009033 2020 -2.01818037033081 2021 -1.83683395385742 2022 -1.81788623332977