Year	Number
1996	1.55765902996063
1998	1.64124596118927
2000	1.79224491119385
2002	1.73382663726807
2003	1.68371534347534
2004	1.63682568073273
2005	1.55062913894653
2006	1.49548137187958
2007	1.64546430110931
2008	1.56200671195984
2009	1.54901349544525
2010	1.62086713314056
2011	1.61533617973328
2012	1.65106618404388
2013	1.61979234218597
2014	1.80034029483795
2015	1.72945630550385
2016	1.90037965774536
2017	1.87512159347534
2018	1.7912358045578
2019	1.65198791027069
2020	1.58489263057709
2021	1.72331547737122
2022	1.62011301517487