Year	Number
1996	1.71339905261993
1998	1.7568027973175
2000	1.72206687927246
2002	1.76704657077789
2003	1.84277212619781
2004	1.79539239406586
2005	1.71280241012573
2006	1.75673854351044
2007	1.74388742446899
2008	1.75908350944519
2009	1.73300874233246
2010	1.75771832466125
2011	1.73315370082855
2012	1.75977957248688
2013	1.77010262012482
2014	1.91871964931488
2015	1.79047870635986
2016	1.71689772605896
2017	1.64458847045898
2018	1.67455554008484
2019	1.69447183609009
2020	1.61424505710602
2021	1.63928818702698
2022	1.51008522510529