Year	Percent of Total
1960-01-01	37.0992812406652
1961-01-01	37.2807601609837
1962-01-01	37.5094411025651
1963-01-01	37.7261541770156
1964-01-01	37.8532594512822
1965-01-01	37.8716053918047
1966-01-01	37.9748247464288
1967-01-01	37.9366799392969
1968-01-01	37.8128314617786
1969-01-01	37.6648663825255
1970-01-01	37.5343211038065
1971-01-01	37.4553809453405
1972-01-01	37.3590520635037
1973-01-01	37.2432711244706
1974-01-01	37.0747122655052
1975-01-01	36.8431641659826
1976-01-01	36.6272257481273
1977-01-01	36.3441294871048
1978-01-01	36.0116230660796
1979-01-01	35.6578842537800
1980-01-01	35.3048676955400
1981-01-01	34.9758371462799
1982-01-01	34.6722306550349
1983-01-01	34.3839807711827
1984-01-01	34.0986541303679
1985-01-01	33.8156103487391
1986-01-01	33.6563913776543
1987-01-01	33.4808671718891
1988-01-01	33.2971224879336
1989-01-01	33.1057415684744
1990-01-01	32.9053494727728
1991-01-01	32.7898059812463
1992-01-01	32.6002539609144
1993-01-01	32.3631981670715
1994-01-01	32.1085224076707
1995-01-01	31.8443674273221
1996-01-01	31.5011054915937
1997-01-01	31.1931717628442
1998-01-01	30.8848167933050
1999-01-01	30.5291489080573
2000-01-01	30.1145062052235
2001-01-01	29.7381266842340
2002-01-01	29.3112916684249
2003-01-01	28.8593014936463
2004-01-01	28.4281956965360
2005-01-01	28.0438328261167
2006-01-01	27.7439081678648
2007-01-01	27.4713332339267
2008-01-01	27.2301389561029
2009-01-01	27.0172479411961
2010-01-01	26.8273876402437
2011-01-01	26.6817186533165
2012-01-01	26.5474514895767
2013-01-01	26.4238458276173
2014-01-01	26.3029778812423
2015-01-01	26.1781976716039
2016-01-01	26.0637360790754
2017-01-01	25.9411116831070