Year Number 1996 -1.56857550144196 1998 -1.56888091564178 2000 0.274133086204529 2002 -0.83753502368927 2003 -0.429828256368637 2004 -0.59241133928299 2005 -0.509093940258026 2006 -1.11040985584259 2007 -1.20347332954407 2008 -1.05070447921753 2009 -1.20296549797058 2010 -1.18515872955322 2011 -1.1867653131485 2012 -1.14376664161682 2013 -1.2126704454422 2014 -1.11254811286926 2015 -1.13323724269867 2016 -1.17557942867279 2017 -1.17624771595001 2018 -1.13863778114319 2019 -1.12843763828278 2020 -1.19682133197784 2021 -1.02632677555084 2022 -0.883395969867706