Year	Number
1996	1.69525694847107
1998	1.74252772331238
2000	1.74453032016754
2002	1.7072594165802
2003	1.70947313308716
2004	1.73802030086517
2005	1.7526228427887
2006	1.76974618434906
2007	1.76987528800964
2008	1.74962913990021
2009	1.80702006816864
2010	1.81173205375671
2011	1.81257343292236
2012	1.85268175601959
2013	1.82533991336823
2014	1.973513007164
2015	1.90730941295624
2016	1.84650659561157
2017	1.75801718235016
2018	1.74473142623901
2019	1.73514080047607
2020	1.70814049243927
2021	1.69880509376526
2022	1.65742564201355