Year	Number
1996	1.44196474552155
1998	1.43196630477905
2000	1.5010689496994
2002	1.5242440700531
2003	1.20381569862366
2004	1.08433735370636
2005	1.07349538803101
2006	1.0467928647995
2007	1.1181892156601
2008	1.06538677215576
2009	1.00118267536163
2010	1.04096102714539
2011	1.10029304027557
2012	0.914910674095154
2013	0.959233462810516
2014	0.951779723167419
2015	0.887059271335602
2016	0.852912425994873
2017	0.854936242103577
2018	0.931788921356201
2019	0.967484951019287
2020	0.920160233974457
2021	0.928524494171143
2022	0.86500883102417