Year	Percent of Total
1960-01-01	3.02158974974494
1961-01-01	3.02970438890324
1962-01-01	3.04505491820730
1963-01-01	3.06579275316434
1964-01-01	3.08957275700518
1965-01-01	3.11602576966459
1966-01-01	3.15755949691448
1967-01-01	3.20243581497719
1968-01-01	3.25061581606863
1969-01-01	3.30354427015127
1970-01-01	3.36281807334874
1971-01-01	3.43275248108894
1972-01-01	3.50499833594241
1973-01-01	3.57996996607279
1974-01-01	3.65681127113093
1975-01-01	3.73418225456480
1976-01-01	3.81311245146984
1977-01-01	3.88408882446863
1978-01-01	3.94867250857620
1979-01-01	4.00824513990606
1980-01-01	4.06414404158523
1981-01-01	4.11563532316353
1982-01-01	4.16652123142924
1983-01-01	4.21756572571459
1984-01-01	4.26978762537216
1985-01-01	4.32527187240063
1986-01-01	4.39245322897009
1987-01-01	4.46088396709016
1988-01-01	4.53263428081032
1989-01-01	4.61129761788433
1990-01-01	4.69897399705103
1991-01-01	4.77993632167787
1992-01-01	4.86764865696219
1993-01-01	4.96135293462684
1994-01-01	5.05921434805835
1995-01-01	5.16088917852441
1996-01-01	5.25807872257371
1997-01-01	5.35714722114738
1998-01-01	5.46123253524406
1999-01-01	5.57382279784749
2000-01-01	5.69785371994957
2001-01-01	5.83361981266003
2002-01-01	5.98052669765043
2003-01-01	6.13785215649844
2004-01-01	6.30314317663226
2005-01-01	6.47568965034237
2006-01-01	6.65044557711508
2007-01-01	6.82430748450212
2008-01-01	7.00788891226746
2009-01-01	7.21624378963532
2010-01-01	7.45780237961138
2011-01-01	7.70720582270436
2012-01-01	7.98988509540575
2013-01-01	8.29387466133888
2014-01-01	8.60043194274394
2015-01-01	8.90106434224681
2016-01-01	9.18832250352770
2017-01-01	9.46764921055190