Year	Number
1996	1.32520198822021
1998	1.37710535526276
2000	1.57533061504364
2002	1.62029254436493
2003	1.51723217964172
2004	1.45700466632843
2005	1.44469714164734
2006	1.45382654666901
2007	1.48559415340424
2008	1.21502387523651
2009	1.1908872127533
2010	1.02225363254547
2011	1.24400973320007
2012	1.24503207206726
2013	1.28713369369507
2014	1.24697458744049
2015	1.29848098754883
2016	1.34658873081207
2017	1.33768498897552
2018	1.39457714557648
2019	1.61964797973633
2020	1.37493765354156
2021	1.3721786737442
2022	1.26293528079987