Year	Percent of Total
1960-01-01	42.9895922421159
1961-01-01	43.2366845758279
1962-01-01	43.4287382398626
1963-01-01	43.5727632267366
1964-01-01	43.6665182571107
1965-01-01	43.7110447857978
1966-01-01	43.9368083349305
1967-01-01	44.0731195799228
1968-01-01	44.1455868764164
1969-01-01	44.1830403385148
1970-01-01	44.2018859385540
1971-01-01	44.3923932777978
1972-01-01	44.5359659093135
1973-01-01	44.6401809132045
1974-01-01	44.7072424734979
1975-01-01	44.7412342163740
1976-01-01	44.9128927808814
1977-01-01	45.0224669125072
1978-01-01	45.0901926346777
1979-01-01	45.1333495111779
1980-01-01	45.1586028837265
1981-01-01	45.3527396439181
1982-01-01	45.4861687350191
1983-01-01	45.5662104637192
1984-01-01	45.5960582110788
1985-01-01	45.5785808423047
1986-01-01	45.6764302211661
1987-01-01	45.7042714989073
1988-01-01	45.6732316615192
1989-01-01	45.5915422494174
1990-01-01	45.4635270673777
1991-01-01	45.4212340314028
1992-01-01	45.3183149293088
1993-01-01	45.1680346704779
1994-01-01	44.9846720973812
1995-01-01	44.7787037850061
1996-01-01	44.7352703578338
1997-01-01	44.6556300139038
1998-01-01	44.5497096552584
1999-01-01	44.4245423388322
2000-01-01	44.2857651333352
2001-01-01	44.2781899602741
2002-01-01	44.2321800075094
2003-01-01	44.1626394890384
2004-01-01	44.0844960169912
2005-01-01	44.0038951961655
2006-01-01	43.9949065608150
2007-01-01	43.9634010930912
2008-01-01	43.9097077468556
2009-01-01	43.8308134421312
2010-01-01	43.7261239407195
2011-01-01	43.6512641647621
2012-01-01	43.5414734603512
2013-01-01	43.4012708056916
2014-01-01	43.2343434509807
2015-01-01	43.0429529373166
2016-01-01	42.8802971457273
2017-01-01	42.6824658475434