Year	Percent of Total
1960-01-01	3.22117400193153
1961-01-01	3.30653802909795
1962-01-01	3.40318899162398
1963-01-01	3.49366081452893
1964-01-01	3.55833659320900
1965-01-01	3.58925099263860
1966-01-01	3.59833892476942
1967-01-01	3.58163804233231
1968-01-01	3.55325413930792
1969-01-01	3.52874394868145
1970-01-01	3.51554504958545
1971-01-01	3.54365733565177
1972-01-01	3.57408906872060
1973-01-01	3.59844721998164
1974-01-01	3.60680078977724
1975-01-01	3.59597486375537
1976-01-01	3.58177684440571
1977-01-01	3.55168154271318
1978-01-01	3.51325799900573
1979-01-01	3.47559462006898
1980-01-01	3.44347819791532
1981-01-01	3.43516116196101
1982-01-01	3.43154772709810
1983-01-01	3.42668690821008
1984-01-01	3.41327769031792
1985-01-01	3.38964025595251
1986-01-01	3.38283119787936
1987-01-01	3.37060570166349
1988-01-01	3.36032071579878
1989-01-01	3.36129157113134
1990-01-01	3.37887310719241
1991-01-01	3.41395182683773
1992-01-01	3.45788510204924
1993-01-01	3.51129671684123
1994-01-01	3.57557983845642
1995-01-01	3.65205548323644
1996-01-01	3.76502456614209
1997-01-01	3.89388452890585
1998-01-01	4.03524793797625
1999-01-01	4.18325160626574
2000-01-01	4.33506201645349
2001-01-01	4.46369387993278
2002-01-01	4.58771336037460
2003-01-01	4.70843995499994
2004-01-01	4.82582731931946
2005-01-01	4.93964616001647
2006-01-01	5.05205842338108
2007-01-01	5.15786029162151
2008-01-01	5.26004128142524
2009-01-01	5.36179966254776
2010-01-01	5.46720152262453
2011-01-01	5.51705971049408
2012-01-01	5.56972401021598
2013-01-01	5.63577736692367
2014-01-01	5.73198695799561
2015-01-01	5.86978507570615
2016-01-01	6.02083403725139
2017-01-01	6.21071489613449