Year	Number
1996	1.48148429393768
1998	1.23130452632904
2000	1.45614349842072
2002	1.51094317436218
2003	1.50187790393829
2004	1.46957302093506
2005	1.51510655879974
2006	1.56890881061554
2007	1.61616551876068
2008	1.48888456821442
2009	1.51645278930664
2010	1.57068610191345
2011	1.54886770248413
2012	1.52908289432526
2013	1.54434037208557
2014	1.69703912734985
2015	1.71191465854645
2016	1.8065539598465
2017	1.77483832836151
2018	1.75632679462433
2019	1.71493887901306
2020	1.57793474197388
2021	1.62516117095947
2022	1.52229499816895