Year	Percent of Total
1960-01-01	42.9522940113241
1961-01-01	43.2531020742376
1962-01-01	43.4703283055417
1963-01-01	43.6161357972809
1964-01-01	43.6879586302658
1965-01-01	43.6864780967530
1966-01-01	43.9039999618205
1967-01-01	44.0089011092414
1968-01-01	44.0294109014797
1969-01-01	43.9986157158684
1970-01-01	43.9385369306057
1971-01-01	44.1056372040792
1972-01-01	44.2074532486320
1973-01-01	44.2575079521103
1974-01-01	44.2637739808332
1975-01-01	44.2344110789759
1976-01-01	44.3771294690872
1977-01-01	44.4145325528100
1978-01-01	44.3835489292985
1979-01-01	44.3159957279022
1980-01-01	44.2196542280934
1981-01-01	44.5535649086126
1982-01-01	44.8445243597857
1983-01-01	45.0677958442397
1984-01-01	45.1806783685422
1985-01-01	45.1578104657087
1986-01-01	45.7589982189417
1987-01-01	46.2130346065441
1988-01-01	46.5507735288600
1989-01-01	46.8571159038174
1990-01-01	47.2064892419780
1991-01-01	46.5062901109994
1992-01-01	45.9334865584966
1993-01-01	45.4927804511787
1994-01-01	45.1337132231464
1995-01-01	44.8034003395618
1996-01-01	44.9466378865097
1997-01-01	45.0074487986032
1998-01-01	45.0072067214494
1999-01-01	44.9910317785137
2000-01-01	44.9898041736056
2001-01-01	45.1600693279239
2002-01-01	45.3035001983839
2003-01-01	45.4239975882249
2004-01-01	45.5107776143059
2005-01-01	45.5562591914093
2006-01-01	45.6990041008540
2007-01-01	45.7767795378727
2008-01-01	45.8011810691040
2009-01-01	45.7848756824023
2010-01-01	45.7342090601268
2011-01-01	45.7141132936138
2012-01-01	45.6504648628405
2013-01-01	45.5443692779991
2014-01-01	45.3935271083582
2015-01-01	45.1989991964140
2016-01-01	45.0188654139950
2017-01-01	44.7901963386900