Year	Number
1996	1.28849947452545
1998	1.02412986755371
2000	1.12981116771698
2002	1.26080238819122
2003	0.85823780298233
2004	0.709136724472046
2005	0.79377418756485
2006	0.856375813484192
2007	0.757325053215027
2008	0.620571196079254
2009	0.820824682712555
2010	0.810646176338196
2011	0.95453542470932
2012	0.923599720001221
2013	0.940082728862762
2014	0.701269447803497
2015	0.577092111110687
2016	0.429606109857559
2017	0.417606323957443
2018	0.39363044500351
2019	0.45831623673439
2020	0.521023035049438
2021	0.662566304206848
2022	0.575668811798096