Year	Number
1996	1.37324202060699
1998	1.26424825191498
2000	1.23428380489349
2002	1.25507593154907
2003	1.2221474647522
2004	1.20174181461334
2005	1.20563590526581
2006	1.16392028331757
2007	1.10266256332397
2008	1.1413848400116
2009	1.00437831878662
2010	1.07051432132721
2011	0.97444885969162
2012	0.983262956142426
2013	0.867901861667633
2014	0.72564971446991
2015	0.679679214954376
2016	0.682798445224762
2017	0.53955864906311
2018	0.500147342681885
2019	0.445289075374603
2020	0.405644178390503
2021	0.419716477394104
2022	0.424218326807022