Year	Number
2000	6.406497948
2001	6.4816689466
2002	6.5568399453
2003	6.6320109439
2004	6.7071819425
2005	6.7823529412
2006	6.7823529412
2007	6.7823529412
2008	6.7823529412
2009	6.7823529412
2010	6.7823529412
2011	6.7823529412
2012	6.7823529412
2013	6.7823529412
2014	6.7823529412
2015	6.7823529412
2016	6.7823529412
2017	6.7823529412
2018	6.7823529412
2019	6.7823529412
2020	6.7823529412