Year	Hours Per Week
1980	53.9
1981	53.6
1982	55.9
1983	55.4
1984	55.1
1985	55.1
1986	53.9
1987	55.4
1988	55.8
1989	54.5
1990	53.8
1991	53.4
1992	52.5
1993	52.7
1994	52.4
1995	52.5
1996	52.3
1997	51.4
1998	50.1
1999	50.4
2000	50.6
2001	50.4
2002	49.8
2003	49.1
2004	48.7
2005	48.1
2006	47.9
2007	47.1
2008	46
2009	45.9
2010	45.1
2011	43.9
2012	44.6
2013	43.1
2014	43.8
2015	43.6
2016	43
2017	42.8