Year	Percent
2005-01-01	19.6923482320175
2006-01-01	19.2769281776127
2007-01-01	19.6782275255354
2008-01-01	20.0368482189879
2009-01-01	20.9798690336369
2010-01-01	21.2803711424777
2011-01-01	21.5237809761279
2012-01-01	21.1971833469303
2013-01-01	21.5102117116978
2014-01-01	21.7423277179876
2015-01-01	22.0143779054621
2016-01-01	22.2807642880337
2017-01-01	22.4191202759400