Year	%
2000	3.360375351579382
2001	3.2260270062370653
2002	3.1250351073635843
2003	2.9769408421087538
2004	2.839536474509338
2005	2.7378152475791597
2006	2.609869735407402
2007	2.5465470328676063
2008	2.456572845631772
2009	2.3579600931013123
2010	2.2453775504141222
2011	2.152423420352461
2012	2.019302133555866
2013	1.9328890697750234
2014	1.855567579509372
2015	1.785016051752932
2016	1.6911565114907021
2017	1.618405769452464
2018	1.543860815084528
2019	1.4817058132206877
2020	1.4305319613453187