Year	Number
1996	1.93155193328857
1998	1.9275484085083
2000	1.94582056999207
2002	1.91821336746216
2003	1.89939785003662
2004	1.88619542121887
2005	1.90166938304901
2006	1.80377161502838
2007	1.82794570922852
2008	1.80470788478851
2009	1.74314093589783
2010	1.74979496002197
2011	1.72214198112488
2012	1.81180202960968
2013	1.79608643054962
2014	1.99034976959229
2015	1.90945196151733
2016	1.90683150291443
2017	1.88840484619141
2018	1.88787722587585
2019	1.86311888694763
2020	1.77829492092133
2021	1.76821339130402
2022	1.75180673599243