Year	Number
1996	1.89194011688232
1998	1.95630431175232
2000	1.67170011997223
2002	1.56194162368774
2003	1.65078556537628
2004	1.75323987007141
2005	1.63162207603455
2006	1.69531941413879
2007	1.71598720550537
2008	1.79991269111633
2009	1.82373833656311
2010	1.81236732006073
2011	1.96411323547363
2012	1.84479916095734
2013	1.81913685798645
2014	1.94383800029755
2015	1.91034615039825
2016	2.02746391296387
2017	2.08128786087036
2018	2.00085973739624
2019	1.8710173368454
2020	1.87444794178009
2021	1.80264282226563
2022	1.86519300937653