Year	Hours per Week
2001-01-01	36.5
2002-01-01	40.9
2003-01-01	41.5
2004-01-01	39.3
2005-01-01	36.4
2006-01-01	38.3
2007-01-01	40.4
2008-01-01	39.4
2009-01-01	39.7
2010-01-01	42.3
2011-01-01	41.3
2012-01-01	40.9