Year	Hours
1978-01-01	1840
1979-01-01	1859
1980-01-01	1834
1981-01-01	1843
1982-01-01	1794
1983-01-01	1784
1984-01-01	1807
1985-01-01	1799
1986-01-01	1806
1987-01-01	1822
1988-01-01	1812
1989-01-01	1810
1990-01-01	1792
1991-01-01	1795
1992-01-01	1809
1993-01-01	1796
1994-01-01	1807
1995-01-01	1805
1996-01-01	1775
1997-01-01	1801
1998-01-01	1802
1999-01-01	1797
2000-01-01	1799
2001-01-01	1749
2002-01-01	1755
2003-01-01	1763
2004-01-01	1744
2005-01-01	1754
2006-01-01	1727
2007-01-01	1699
2008-01-01	1750
2009-01-01	1711
2010-01-01	1707
2011-01-01	1715