Year	Hours
1984-01-01	147.250000000000
1985-01-01	145.325000000000
1986-01-01	144.633333333333
1987-01-01	147.991666666667
1988-01-01	147.966666666667
1989-01-01	145.466666666667
1990-01-01	143.450000000000
1991-01-01	141.250000000000
1992-01-01	137.500000000000
1993-01-01	144.275000000000
1994-01-01	146.625000000000
1995-01-01	147.075000000000
1996-01-01	148.075000000000
1997-01-01	148.875000000000
1998-01-01	149.000000000000
1999-01-01	149.600000000000
2000-01-01	149.650000000000
2001-01-01	147.150000000000
2002-01-01	147.250000000000
2003-01-01	148.100000000000
2004-01-01	150.525000000000
2005-01-01	150.200000000000
2006-01-01	149.925000000000
2007-01-01	148.200000000000
2008-01-01	148.700000000000
2009-01-01	147.200000000000
2010-01-01	151.525000000000
2011-01-01	151.400000000000
2012-01-01	153.050000000000
2013-01-01	150.225000000000
2014-01-01	150.775000000000
2015-01-01	151.350000000000
2016-01-01	151.625000000000
2017-01-01	149.950000000000