Year	Percent of Total
1960-01-01	4.32692465064303
1961-01-01	4.24759723258674
1962-01-01	4.17122167679651
1963-01-01	4.09684550484725
1964-01-01	4.02305429070899
1965-01-01	3.95015688888441
1966-01-01	3.92377281986515
1967-01-01	3.89583655099541
1968-01-01	3.86693006847067
1969-01-01	3.83777960460634
1970-01-01	3.80878824461564
1971-01-01	3.80613646423668
1972-01-01	3.80125220700339
1973-01-01	3.79651871857303
1974-01-01	3.79354462736743
1975-01-01	3.79288158793911
1976-01-01	3.80335348353122
1977-01-01	3.81284243274319
1978-01-01	3.82203758164311
1979-01-01	3.83102263213526
1980-01-01	3.83981204932962
1981-01-01	3.84813948037314
1982-01-01	3.85475311100803
1983-01-01	3.86071044353009
1984-01-01	3.86624860951797
1985-01-01	3.87172828372242
1986-01-01	3.88168053437767
1987-01-01	3.88675093350558
1988-01-01	3.88985899804617
1989-01-01	3.89432240584026
1990-01-01	3.90213046390066
1991-01-01	3.91596636226974
1992-01-01	3.93211134504618
1993-01-01	3.94982644902473
1994-01-01	3.96720098052296
1995-01-01	3.98388581185958
1996-01-01	4.00767950417386
1997-01-01	4.02657783003333
1998-01-01	4.04390624340281
1999-01-01	4.06374304327065
2000-01-01	4.08823686212755
2001-01-01	4.11895184368786
2002-01-01	4.15053649725055
2003-01-01	4.18357191382479
2004-01-01	4.21734735903828
2005-01-01	4.25143080843648
2006-01-01	4.29891994660801
2007-01-01	4.33844818471339
2008-01-01	4.37075214756701
2009-01-01	4.39677908798094
2010-01-01	4.41706493957658
2011-01-01	4.43914379981452
2012-01-01	4.45885315371882
2013-01-01	4.47448125431261
2014-01-01	4.48298668724964
2015-01-01	4.48490178078671
2016-01-01	4.49302268246975
2017-01-01	4.49493900126008