Year	Number
1993	3.1424375918
1994	3.2056929854
1995	3.2689483791
1996	3.3322037727
1997	3.3954591664
1998	3.45871456
1999	3.5219699537
2000	3.5852253473
2001	3.648480741
2002	3.7117361346
2003	3.7749915283
2004	3.8382469219
2005	3.7533039648
2006	3.9647577093
2007	3.9916789036
2008	4.0186000979
2009	4.0455212922
2010	3.8969652472
2011	3.7484092022
2012	3.5998531571
2013	3.4512971121
2014	3.3027410671
2015	3.154185022
2016	3.3950073421
2017	3.3950073421
2018	3.3950073421
2019	3.3950073421
2020	3.3950073421