Year	Percent of Total
1960-01-01	5.69837935174070
1961-01-01	5.57379156025706
1962-01-01	5.44993154462373
1963-01-01	5.33976521290848
1964-01-01	5.25759127491510
1965-01-01	5.21130946058205
1966-01-01	5.22737491678987
1967-01-01	5.26596996349707
1968-01-01	5.31593209803002
1969-01-01	5.35907472296964
1970-01-01	5.38585213908532
1971-01-01	5.48045092298721
1972-01-01	5.53650857992862
1973-01-01	5.57232487840877
1974-01-01	5.61335885982316
1975-01-01	5.67031121075046
1976-01-01	5.79043418831206
1977-01-01	5.92302719906595
1978-01-01	6.04185028393915
1979-01-01	6.10825749423922
1980-01-01	6.10608330707414
1981-01-01	6.07124765837853
1982-01-01	5.98541922435941
1983-01-01	5.87271076891033
1984-01-01	5.76500988225885
1985-01-01	5.68037353073450
1986-01-01	5.65933095000134
1987-01-01	5.64435973039431
1988-01-01	5.65610760074846
1989-01-01	5.72328989849382
1990-01-01	5.85966071387762
1991-01-01	6.10529602236805
1992-01-01	6.41939048655270
1993-01-01	6.74881490531460
1994-01-01	7.01398878531827
1995-01-01	7.17106426734192
1996-01-01	7.21323947192751
1997-01-01	7.12104133091067
1998-01-01	6.96554420325502
1999-01-01	6.85060123672207
2000-01-01	6.82515922608759
2001-01-01	7.05257343913761
2002-01-01	7.34140779821054
2003-01-01	7.59951616053360
2004-01-01	7.72264712741185
2005-01-01	7.67734968478181
2006-01-01	7.60219595342792
2007-01-01	7.42855014612071
2008-01-01	7.20715777390362
2009-01-01	6.99719843404938
2010-01-01	6.82312115097918
2011-01-01	6.82438317621151
2012-01-01	6.81487974330867
2013-01-01	6.78393424355782
2014-01-01	6.75156633669719
2015-01-01	6.75390858455334
2016-01-01	6.84021046339573
2017-01-01	6.99109599225993