Year	Percent of Total
1960-01-01	44.7080151274182
1961-01-01	44.8390996488400
1962-01-01	44.7542687304512
1963-01-01	44.5632080427301
1964-01-01	44.4118042587999
1965-01-01	44.3619133642942
1966-01-01	44.6216130158697
1967-01-01	44.9059304247649
1968-01-01	45.1949481198449
1969-01-01	45.4354268170445
1970-01-01	45.6004412081266
1971-01-01	45.9649717903620
1972-01-01	46.2175359751091
1973-01-01	46.3874090943658
1974-01-01	46.5089875869495
1975-01-01	46.5981573486134
1976-01-01	46.8594726937570
1977-01-01	47.0480937206410
1978-01-01	47.1760827092853
1979-01-01	47.2427857325655
1980-01-01	47.2461334267931
1981-01-01	47.4403676988745
1982-01-01	47.5136989216668
1983-01-01	47.5133899123872
1984-01-01	47.5094432540479
1985-01-01	47.5499663366433
1986-01-01	47.2774269357095
1987-01-01	46.9986981676195
1988-01-01	46.6853345544455
1989-01-01	46.2582978537651
1990-01-01	45.6561568448940
1991-01-01	45.8767950264870
1992-01-01	45.9512131750594
1993-01-01	45.9358721637679
1994-01-01	45.9438096000235
1995-01-01	46.0606768251528
1996-01-01	46.2687994774174
1997-01-01	46.4807372704434
1998-01-01	46.6848249710596
1999-01-01	46.8212089505264
2000-01-01	46.8527286683078
2001-01-01	46.9734982360857
2002-01-01	46.9750354407560
2003-01-01	46.8958805552901
2004-01-01	46.7988499245585
2005-01-01	46.7203605969488
2006-01-01	46.6338284263126
2007-01-01	46.5746292763173
2008-01-01	46.5159214683187
2009-01-01	46.4051898923260
2010-01-01	46.2154881999486
2011-01-01	46.0355762471286
2012-01-01	45.7246476972388
2013-01-01	45.3434116256555
2014-01-01	44.9741921506315
2015-01-01	44.6524950740050
2016-01-01	44.2719829533913
2017-01-01	43.9892559938447