Year	Number
1996	-1.19465482234955
1998	-1.12208342552185
2000	-0.915324807167053
2002	-1.04421436786652
2003	-1.12732601165771
2004	-1.27454555034637
2005	-1.17498433589935
2006	-1.0954829454422
2007	-1.20494568347931
2008	-1.2003960609436
2009	-1.21717298030853
2010	-1.16155707836151
2011	-1.18604528903961
2012	-1.29328751564026
2013	-1.34157395362854
2014	-1.55671191215515
2015	-1.50964152812958
2016	-1.58632564544678
2017	-1.59746825695038
2018	-1.55884099006653
2019	-1.49794888496399
2020	-1.3631352186203
2021	-1.31993007659912
2022	-1.18539381027222