Year	Number
1996	2.20687246322632
1998	2.19966173171997
2000	2.36823558807373
2002	2.36900973320007
2003	2.3741238117218
2004	2.41011142730713
2005	2.3147189617157
2006	2.45411086082459
2007	2.38947749137878
2008	2.32084584236145
2009	2.24071860313416
2010	2.15166974067688
2011	2.1919150352478
2012	2.22684669494629
2013	2.20017123222351
2014	2.15947580337524
2015	2.21577143669128
2016	2.18605208396912
2017	2.16156053543091
2018	2.17132115364075
2019	2.11400508880615
2020	2.17063069343567
2021	2.23821711540222
2022	2.24697780609131