Year	Percent of Total
1960-01-01	2.27104984238372
1961-01-01	2.30014809481525
1962-01-01	2.31223733444730
1963-01-01	2.31148374572025
1964-01-01	2.30431894460361
1965-01-01	2.29355063245221
1966-01-01	2.36767811260005
1967-01-01	2.43594729170854
1968-01-01	2.49552184070294
1969-01-01	2.54295381385919
1970-01-01	2.57725399622965
1971-01-01	2.66887582657378
1972-01-01	2.74925017787840
1973-01-01	2.81762677490299
1974-01-01	2.87404205925932
1975-01-01	2.91894300121038
1976-01-01	3.00750078864317
1977-01-01	3.08473823301081
1978-01-01	3.15042755436561
1979-01-01	3.20447737314562
1980-01-01	3.24685344096847
1981-01-01	3.33430877860659
1982-01-01	3.41225958544903
1983-01-01	3.47831308675282
1984-01-01	3.52987723539373
1985-01-01	3.56589578835961
1986-01-01	3.63768741914057
1987-01-01	3.69935488892949
1988-01-01	3.75090089781741
1989-01-01	3.79091190585846
1990-01-01	3.81732809714326
1991-01-01	3.80423539332037
1992-01-01	3.77957893219901
1993-01-01	3.74488000182747
1994-01-01	3.70183628707682
1995-01-01	3.65122417212854
1996-01-01	3.59345467752752
1997-01-01	3.52920390101180
1998-01-01	3.45871984286428
1999-01-01	3.38076110941741
2000-01-01	3.29533383966906
2001-01-01	3.22884680399580
2002-01-01	3.15266980320956
2003-01-01	3.07270359799579
2004-01-01	2.99603628368388
2005-01-01	2.92572024343290
2006-01-01	2.89436113713520
2007-01-01	2.86603752696590
2008-01-01	2.83538602041446
2009-01-01	2.79566828604911
2010-01-01	2.74503261507315
2011-01-01	2.71063186519211
2012-01-01	2.66602610036941
2013-01-01	2.61736717810574
2014-01-01	2.57213913278468
2015-01-01	2.53395584645096
2016-01-01	2.52532434720025
2017-01-01	2.51876552558033