Year	Number
1996	1.51272976398468
1998	1.63800525665283
2000	1.78177714347839
2002	1.71949744224548
2003	1.5846620798111
2004	1.56711328029633
2005	1.48796188831329
2006	1.83704507350922
2007	1.85081696510315
2008	1.91425919532776
2009	1.69592678546906
2010	1.61843299865723
2011	1.59480214118958
2012	1.56388533115387
2013	1.57406163215637
2014	1.75873184204102
2015	1.80811500549316
2016	1.72934794425964
2017	1.57494032382965
2018	1.61936497688293
2019	1.59087955951691
2020	1.4674471616745
2021	1.55254113674164
2022	1.63956081867218