Year	Number
1996	1.45682156085968
1998	1.43966126441956
2000	1.57881200313568
2002	1.54236817359924
2003	1.24610948562622
2004	1.22733986377716
2005	1.19678211212158
2006	1.26811742782593
2007	1.23440885543823
2008	1.22224521636963
2009	1.30772125720978
2010	1.25859427452087
2011	1.30034208297729
2012	1.41833603382111
2013	1.4011402130127
2014	1.40265262126923
2015	1.32649421691895
2016	1.28985404968262
2017	1.24231481552124
2018	1.31924939155579
2019	1.31083822250366
2020	1.17615520954132
2021	1.11522209644318
2022	1.16113972663879