Year	Percent of Total
1960-01-01	2.77836768411833
1961-01-01	2.76639698783643
1962-01-01	2.75401527770020
1963-01-01	2.73598457067559
1964-01-01	2.70730993349616
1965-01-01	2.66598873270173
1966-01-01	2.68257212740852
1967-01-01	2.68859779861380
1968-01-01	2.68414603957821
1969-01-01	2.66941443217986
1970-01-01	2.64469735154412
1971-01-01	2.66401504573737
1972-01-01	2.67274369880117
1973-01-01	2.67176635233259
1974-01-01	2.66218882516613
1975-01-01	2.64499214080126
1976-01-01	2.67050885948483
1977-01-01	2.68849147602034
1978-01-01	2.69933063128273
1979-01-01	2.70445888415864
1980-01-01	2.70481858983263
1981-01-01	2.73661463441332
1982-01-01	2.76261809413427
1983-01-01	2.78371977326681
1984-01-01	2.80097053606065
1985-01-01	2.81554370282920
1986-01-01	2.84964623912818
1987-01-01	2.87882888719569
1988-01-01	2.90280094100342
1989-01-01	2.92132923916233
1990-01-01	2.93478480122808
1991-01-01	2.97415310443777
1992-01-01	3.00516809538928
1993-01-01	3.02887295645460
1994-01-01	3.04653119540788
1995-01-01	3.05920630548829
1996-01-01	3.09118860027513
1997-01-01	3.11561210573996
1998-01-01	3.13374450831176
1999-01-01	3.14753081634235
2000-01-01	3.15848866035847
2001-01-01	3.18920840453508
2002-01-01	3.21715854280117
2003-01-01	3.24114033517426
2004-01-01	3.25997639866935
2005-01-01	3.27399093133191
2006-01-01	3.31148365941957
2007-01-01	3.34294821212440
2008-01-01	3.37035063274373
2009-01-01	3.39570780460794
2010-01-01	3.42111456860131
2011-01-01	3.46324044467262
2012-01-01	3.50245921185719
2013-01-01	3.54291825285976
2014-01-01	3.58951414976047
2015-01-01	3.64506791501075
2016-01-01	3.72538448094747
2017-01-01	3.80820301431483