Year	Number
1996	-1.36154520511627
1998	-1.43743777275085
2000	-1.38408052921295
2002	-1.59419310092926
2003	-1.51242911815643
2004	-1.4624639749527
2005	-1.50078511238098
2006	-1.74897027015686
2007	-1.72125017642975
2008	-1.69949722290039
2009	-1.7011684179306
2010	-1.68054747581482
2011	-1.63760912418365
2012	-1.63794147968292
2013	-1.63140857219696
2014	-1.61666750907898
2015	-1.66077363491058
2016	-1.55957043170929
2017	-1.50373148918152
2018	-1.45992791652679
2019	-1.6273341178894
2020	-1.65873777866364
2021	-1.64286768436432
2022	-1.60957491397858