Year	Hours Per Week
1987	47.8
1988	46.7
1989	46.9
1990	47.6
1991	42.6
1992	42.4
1993	41.5
1994	42
1995	42
1996	41.6
1997	41.6
1998	41.6
1999	42.2
2000	42.1
2001	40.8658
2002	40.8
2003	41.0439
2004	41.2346
2005	41.6091
2006	41.0973
2007	41.423
2008	41.8356
2009	41.2221
2010	41.7049
2011	41.1391
2012	41.1721
2013	41.6951
2014	40.8534
2016	42.236
2017	41.3976