Year	Number
1996	1.3675971031189
1998	1.43221116065979
2000	1.57561349868774
2002	1.42115557193756
2003	1.57526314258575
2004	1.71121954917908
2005	1.59951293468475
2006	1.62376224994659
2007	1.68421590328217
2008	1.76601755619049
2009	1.81692755222321
2010	1.69597673416138
2011	1.85212278366089
2012	1.77889716625214
2013	1.79121994972229
2014	1.85737347602844
2015	1.77741026878357
2016	1.88573145866394
2017	1.9225355386734
2018	1.89657723903656
2019	1.86464607715607
2020	1.81394696235657
2021	1.83118271827698
2022	1.89489328861237