Year	Number
1996	0.750565767288208
1998	0.984140694141388
2000	0.796505093574524
2002	1.26554250717163
2003	1.53687572479248
2004	1.56783330440521
2005	1.60160768032074
2006	1.53962767124176
2007	1.51000499725342
2008	1.47821688652039
2009	1.48886930942535
2010	1.53603065013885
2011	1.54570031166077
2012	1.57356703281403
2013	1.56582093238831
2014	1.85651195049286
2015	1.79075849056244
2016	1.6841539144516
2017	1.67986571788788
2018	1.72961246967316
2019	1.56552135944366
2020	1.55032110214233
2021	1.41228151321411
2022	1.2792032957077