Year	Number
1996	1.41271877288818
1998	1.47338783740997
2000	1.72011208534241
2002	1.7531840801239
2003	1.6870174407959
2004	1.61962687969208
2005	1.59494686126709
2006	1.50111103057861
2007	1.48869705200195
2008	1.44586837291718
2009	1.45967149734497
2010	1.42360687255859
2011	1.39347100257874
2012	1.40076518058777
2013	1.38517248630524
2014	1.28219723701477
2015	1.02799820899963
2016	0.982591867446899
2017	1.06380665302277
2018	0.891700327396393
2019	0.835154116153717
2020	0.981748819351196
2021	0.963134944438934
2022	0.891491711139679