Year	Number
1996	1.31814324855804
1998	1.33475875854492
2000	1.31340384483337
2002	1.31074380874634
2003	1.33278954029083
2004	1.25959527492523
2005	1.26966309547424
2006	1.25131320953369
2007	1.26187098026276
2008	0.797165334224701
2009	1.10914754867554
2010	1.12129557132721
2011	1.34440243244171
2012	1.34624350070953
2013	1.35189199447632
2014	1.01423156261444
2015	0.973423421382904
2016	0.482424229383469
2017	0.481270760297775
2018	0.456312149763107
2019	0.428329825401306
2020	0.439358830451965
2021	0.468788921833038
2022	0.457741022109985