Year	Percent of Total
1960-01-01	40.9724769480739
1961-01-01	41.3156643592001
1962-01-01	41.6902899382805
1963-01-01	42.0429891024206
1964-01-01	42.2836558083231
1965-01-01	42.3770075474993
1966-01-01	42.6174836974411
1967-01-01	42.7025824710588
1968-01-01	42.6853314556524
1969-01-01	42.6533806975498
1970-01-01	42.6613721950768
1971-01-01	42.8647341141158
1972-01-01	43.0801475084683
1973-01-01	43.3020560789757
1974-01-01	43.4998569825519
1975-01-01	43.6524632896505
1976-01-01	44.0327834275675
1977-01-01	44.3348819190647
1978-01-01	44.5845543166011
1979-01-01	44.8185995209826
1980-01-01	45.0578695854338
1981-01-01	45.4237557988680
1982-01-01	45.7445786464489
1983-01-01	46.0262732512558
1984-01-01	46.2700386714213
1985-01-01	46.4843706269327
1986-01-01	46.7878159971589
1987-01-01	47.0193989112971
1988-01-01	47.1981554128430
1989-01-01	47.3400361922482
1990-01-01	47.4515848033334
1991-01-01	47.6998107829799
1992-01-01	47.8908233921433
1993-01-01	48.0351235424110
1994-01-01	48.1452741698960
1995-01-01	48.2320823480778
1996-01-01	48.4553662451213
1997-01-01	48.6123179378350
1998-01-01	48.7191558780492
1999-01-01	48.7925533515563
2000-01-01	48.8437780302183
2001-01-01	49.0067080595063
2002-01-01	49.1093949146655
2003-01-01	49.1575130268237
2004-01-01	49.1470326135528
2005-01-01	49.0713974726754
2006-01-01	49.1008527771703
2007-01-01	49.0541503166196
2008-01-01	48.9412073673275
2009-01-01	48.7788175838445
2010-01-01	48.5818782250020
2011-01-01	48.4685991977476
2012-01-01	48.3055866781423
2013-01-01	48.1013986352093
2014-01-01	47.8590343977400
2015-01-01	47.5797023044435
2016-01-01	47.3838687073963
2017-01-01	47.1426095876280