Year	Number
2006	2.3875770654
2007	4.4604981404
2008	5.2868252
2009	5.2225853714
2010	4.9802772456
2011	5.3533190578
2012	4.962245013
2013	5.3071114617
2014	4.4348022089
2015	5.284571171
2016	5.3048574327
2017	6.0599571734
2018	6.2633832976
2019	6.3322438859
2020	6.0007889102