Year	Number
1996	1.64725470542908
1998	1.71499538421631
2000	1.66548609733582
2002	1.66139602661133
2003	1.69705653190613
2004	1.68714725971222
2005	1.65014719963074
2006	1.80108332633972
2007	1.79710018634796
2008	1.79639303684235
2009	1.7967267036438
2010	1.79859042167664
2011	1.72711992263794
2012	1.75642120838165
2013	1.74749934673309
2014	1.88638472557068
2015	1.80727338790894
2016	1.80136454105377
2017	1.76253008842468
2018	1.71509540081024
2019	1.71972894668579
2020	1.61829829216003
2021	1.59374892711639
2022	1.56622016429901