Year	Percent of Total
1960-01-01	2.14851818834120
1961-01-01	2.18348609241991
1962-01-01	2.21707694193047
1963-01-01	2.25433852860139
1964-01-01	2.28663829700953
1965-01-01	2.30828142423434
1966-01-01	2.37787250722720
1967-01-01	2.42830962268728
1968-01-01	2.46175178021668
1969-01-01	2.48440791375821
1970-01-01	2.50757347105313
1971-01-01	2.57804317309656
1972-01-01	2.65015098864372
1973-01-01	2.71730143857135
1974-01-01	2.77045846587222
1975-01-01	2.80749227551001
1976-01-01	2.87877347322659
1977-01-01	2.92977563213892
1978-01-01	2.96866497250062
1979-01-01	2.99953687642804
1980-01-01	3.02447676833193
1981-01-01	3.01545703545349
1982-01-01	3.00350195152805
1983-01-01	2.98735365502244
1984-01-01	2.96418220406673
1985-01-01	2.93349506075706
1986-01-01	2.90312018565359
1987-01-01	2.86771335302347
1988-01-01	2.82759029713540
1989-01-01	2.78401340085208
1990-01-01	2.73983211315783
1991-01-01	2.74241094984376
1992-01-01	2.74364664117634
1993-01-01	2.74594935528850
1994-01-01	2.75233428077340
1995-01-01	2.76180498826231
1996-01-01	2.75360442341991
1997-01-01	2.74621975962821
1998-01-01	2.73682451522209
1999-01-01	2.72381255123722
2000-01-01	2.70699861346079
2001-01-01	2.66596877594953
2002-01-01	2.62066009887528
2003-01-01	2.57791719650213
2004-01-01	2.54437916361892
2005-01-01	2.52367394080061
2006-01-01	2.52075591155322
2007-01-01	2.52761975055811
2008-01-01	2.53391095902484
2009-01-01	2.52830027568372
2010-01-01	2.50568951079367
2011-01-01	2.47497227094252
2012-01-01	2.43129638621072
2013-01-01	2.38479146184312
2014-01-01	2.34882566537981
2015-01-01	2.32940093750474
2016-01-01	2.32906434679208
2017-01-01	2.33927204451367