Year	Hours per Week
2001-01-01	39.9
2002-01-01	40.6
2003-01-01	40.9
2004-01-01	41.0
2005-01-01	40.8
2006-01-01	40.5
2007-01-01	40.9
2008-01-01	40.6
2009-01-01	40.5
2010-01-01	39.5
2011-01-01	39.6
2012-01-01	40.6
2013-01-01	40.9
2014-01-01	42.1
2015-01-01	40.8
2016-01-01	40.8
2017-01-01	39.1