Year	Number
1996	1.48829090595245
1998	1.53667593002319
2000	1.46447455883026
2002	1.53391695022583
2003	1.52460896968842
2004	1.61642110347748
2005	1.56574976444244
2006	1.55865693092346
2007	1.60638952255249
2008	1.65094351768494
2009	1.69657874107361
2010	1.69343030452728
2011	1.68484020233154
2012	1.70719468593597
2013	1.72989094257355
2014	1.83872532844543
2015	1.70605802536011
2016	1.72741413116455
2017	1.87920141220093
2018	1.69941985607147
2019	1.71000242233276
2020	1.5925897359848
2021	1.61376404762268
2022	1.67709279060364