Year Number 1996 -0.223502203822136 1998 -0.202992081642151 2000 -0.244871854782104 2002 -0.266611307859421 2003 -0.367893666028976 2004 -0.400920122861862 2005 -0.475531458854675 2006 -0.402620196342468 2007 -0.40977942943573 2008 -0.288044780492783 2009 -0.103854693472385 2010 0.0564144365489483 2011 0.0451417230069637 2012 -0.0769327953457832 2013 -0.0918470323085785 2014 -0.0527190156280994 2015 -0.187204733490944 2016 -0.201229780912399 2017 -0.305652469396591 2018 -0.302387714385986 2019 -0.224174305796623 2020 -0.231702029705048 2021 -0.300649881362915 2022 -0.257250934839249