Year	Percent of Total
1960-01-01	3.10910905767417
1961-01-01	3.09869268541500
1962-01-01	3.07965131585578
1963-01-01	3.05548470572415
1964-01-01	3.03048011813018
1965-01-01	3.00669927698944
1966-01-01	3.00141243935095
1967-01-01	2.99299357816507
1968-01-01	2.98565478008401
1969-01-01	2.98363600258805
1970-01-01	2.98918335619856
1971-01-01	3.02047254820791
1972-01-01	3.05260854203252
1973-01-01	3.08311246822061
1974-01-01	3.10931808875232
1975-01-01	3.13015648046002
1976-01-01	3.16365581155480
1977-01-01	3.18930671158912
1978-01-01	3.20658682748175
1979-01-01	3.21431053631333
1980-01-01	3.21266119807495
1981-01-01	3.21565013517643
1982-01-01	3.20862463345961
1983-01-01	3.19552025163408
1984-01-01	3.18082578774956
1985-01-01	3.16710136992273
1986-01-01	3.17134204830070
1987-01-01	3.17355770983114
1988-01-01	3.17121845356814
1989-01-01	3.16085442432174
1990-01-01	3.14198599752809
1991-01-01	3.13348651712680
1992-01-01	3.11699247240351
1993-01-01	3.09873270237093
1994-01-01	3.08621534337404
1995-01-01	3.08346094831276
1996-01-01	3.11614599239116
1997-01-01	3.15218564176844
1998-01-01	3.18933478923489
1999-01-01	3.22456254215256
2000-01-01	3.25666098600991
2001-01-01	3.30571340865218
2002-01-01	3.35002211376086
2003-01-01	3.39121610940289
2004-01-01	3.43209697886333
2005-01-01	3.47602262770518
2006-01-01	3.60211243397477
2007-01-01	3.73033017300589
2008-01-01	3.85847281329670
2009-01-01	3.99102029812576
2010-01-01	4.13749032505428
2011-01-01	4.21357976463387
2012-01-01	4.29735966278257
2013-01-01	4.38596642650942
2014-01-01	4.47728402186049
2015-01-01	4.57191256718106
2016-01-01	4.68726247994318
2017-01-01	4.80264080293494