Year	%
2000	3.11348801035388
2001	3.05772435865307
2002	3.05961254362217
2003	2.89278439482387
2004	2.86668768249484
2005	2.85124566138117
2006	2.76006737088644
2007	2.42258658645679
2008	2.4847226990928
2009	2.50254122953573
2010	2.26645403387177
2011	2.1987525539192
2012	2.06513207363239
2013	1.83169678350779
2014	1.95931619810301
2015	1.78619467969753
2016	1.75054100086866
2017	1.76332959275796
2018	1.5090865418153
2019	1.55476678973034
2020	1.5157636041432