Year	Number
1996	1.5002189874649
1998	1.56696021556854
2000	1.56463289260864
2002	1.51690554618835
2003	1.55444955825806
2004	1.41830444335938
2005	1.5282701253891
2006	1.59266018867493
2007	1.61114573478699
2008	1.62871420383453
2009	1.59132015705109
2010	1.63102221488953
2011	1.59098601341248
2012	1.62034177780151
2013	1.54929387569427
2014	1.60693037509918
2015	1.56277310848236
2016	1.58051216602325
2017	1.60738492012024
2018	1.47568666934967
2019	1.42403542995453
2020	1.33538234233856
2021	1.3906421661377
2022	1.37168848514557