Year	%
2000	4.453707204654814
2001	4.280811679572345
2002	4.169170932743774
2003	3.9880088073174633
2004	3.8309394102906373
2005	3.6999090002902872
2006	3.542976987558679
2007	3.4482867183103756
2008	3.340487294841404
2009	3.2140928616773365
2010	3.0693701210705018
2011	2.9370899299284092
2012	2.76460099950068
2013	2.635582302310238
2014	2.503419481592386
2015	2.395919904066553
2016	2.2579065313806277
2017	2.1646653782643543
2018	2.066192081101703
2019	1.9843307693277221
2020	1.9280223801169394