Year	Hours Per Week
1976	38.7
1977	38.8
1978	39
1979	38.9
1980	38.5
1981	38.1
1982	38
1983	38.3
1984	38.8
1985	39
1986	39.1
1987	39
1988	39.4
1989	39.6
1990	39.4
1991	39.2
1992	38.9
1993	39.4
1994	39.2
1995	39.3
1996	39.3
1997	39.5
1998	39.3
1999	39.6
2000	37.2769
2001	36.8727
2002	36.8551
2003	36.7474
2004	36.7586
2005	36.8802
2006	36.9178
2007	36.8825
2008	36.6764
2009	35.7183
2010	36.0929
2011	36.2392
2012	36.3849
2013	36.5764
2014	36.5939
2015	36.5766
2016	36.6778
2017	36.5943