Year	Hours Per Week
1988	46.2
1989	45.8
1990	47.1
1991	46.3
1992	45.4
1993	45.2
1994	46.1
1995	48
1996	46.6
1997	44.3
1998	47.2
1999	45.2
2000	46.5
2001	48.6
2002	48.7
2003	48.7
2004	49.3
2005	51.4
2006	51.9107
2007	49.6238
2009	48.7556
2010	47.7008
2011	47.3597
2012	48.1378
2013	46.9275
2014	47.0514
2015	46.7002
2016	46.3756
2017	45.9133