Year	Percent
2005-01-01	19.9825956610394
2006-01-01	18.1769402445464
2007-01-01	19.7739562260531
2008-01-01	20.7092013238291
2009-01-01	21.3447372122191
2010-01-01	22.1178985107914
2011-01-01	22.6144501155875
2012-01-01	21.2302433629944
2013-01-01	21.8104904501153
2014-01-01	21.1486661545976
2015-01-01	21.8525329033604
2016-01-01	22.2291699103225
2017-01-01	21.7806450655338