Year	Number
1996	1.44020295143127
1998	1.4074912071228
2000	1.47130513191223
2002	1.40723323822021
2003	1.44212782382965
2004	1.50154197216034
2005	1.50705575942993
2006	1.38279473781586
2007	1.3691999912262
2008	1.36807608604431
2009	1.38379085063934
2010	1.41976547241211
2011	1.45372104644775
2012	1.49919033050537
2013	1.43641376495361
2014	1.36174380779266
2015	1.35561084747314
2016	1.35369718074799
2017	1.37772917747498
2018	1.3939208984375
2019	1.26963520050049
2020	1.29803049564362
2021	1.35839426517487
2022	1.31948041915894