Year	Number
1996	1.28616893291473
1998	1.30419409275055
2000	1.32083249092102
2002	1.23703944683075
2003	1.20097935199738
2004	1.17211830615997
2005	1.17014455795288
2006	1.16447603702545
2007	1.15891206264496
2008	1.18814706802368
2009	1.1825864315033
2010	1.1658923625946
2011	1.19696378707886
2012	1.20560419559479
2013	1.19639348983765
2014	1.16582524776459
2015	1.18986773490906
2016	1.19146013259888
2017	1.18986344337463
2018	1.12343680858612
2019	1.16203200817108
2020	1.12046754360199
2021	1.08812630176544
2022	1.22723925113678