Year	Number
1996	1.59310185909271
1998	1.61003684997559
2000	1.69612085819244
2002	1.55174136161804
2003	1.568514585495
2004	1.55983471870422
2005	1.60669600963593
2006	1.64094340801239
2007	1.49368762969971
2008	1.53245806694031
2009	1.39833772182465
2010	1.4438453912735
2011	1.45509660243988
2012	1.29439389705658
2013	1.26038861274719
2014	1.27628946304321
2015	1.24220669269562
2016	1.48562073707581
2017	1.61907637119293
2018	1.61313998699188
2019	1.33457458019257
2020	1.2384375333786
2021	1.44095718860626
2022	1.42443990707397