Year	Number
1996	1.92191684246063
1998	1.88449275493622
2000	1.87932634353638
2002	1.96259272098541
2003	2.01690196990967
2004	2.09973764419556
2005	1.8879017829895
2006	1.80057287216187
2007	2.01871752738953
2008	1.94697892665863
2009	2.04168105125427
2010	1.96262037754059
2011	1.92519795894623
2012	1.91103565692902
2013	1.78943645954132
2014	1.68177235126495
2015	1.68551158905029
2016	1.66378688812256
2017	1.6754777431488
2018	1.67112922668457
2019	1.67409884929657
2020	1.6703794002533
2021	1.61247062683105
2022	1.57297706604004