Year	%
2000	4.428099516532951
2001	4.309874932567097
2002	4.202121668767514
2003	4.024603188308377
2004	3.911316853279217
2005	3.8126475736045258
2006	3.7056155215789803
2007	3.6540778822600366
2008	3.6297932881436803
2009	3.54689271408746
2010	3.4626598329976095
2011	3.304412809172491
2012	3.189262413648712
2013	3.1133450791136092
2014	3.037580244437725
2015	2.9107952479665915
2016	2.8255259319736097
2017	2.745205805978005
2018	2.667227483649209
2019	2.5804579624856108
2020	2.463183308311915