Year	Number
1996	1.52492046356201
1998	1.6985274553299
2000	1.72488653659821
2002	1.62092781066895
2003	1.54012453556061
2004	1.74025785923004
2005	1.53101277351379
2006	1.5816855430603
2007	1.64327275753021
2008	1.60507559776306
2009	1.50298464298248
2010	1.55227208137512
2011	1.5137984752655
2012	1.5213223695755
2013	1.51700305938721
2014	1.46222817897797
2015	1.43311977386475
2016	1.44152593612671
2017	1.51739835739136
2018	1.53704130649567
2019	1.45355904102325
2020	1.27513825893402
2021	1.29951977729797
2022	1.25599312782288