Year	Percent
1979-01-01	79.0369842787679
1980-01-01	78.1750412929030
1981-01-01	78.7938414518798
1982-01-01	80.0282559171770
1983-01-01	79.3459219803076
1984-01-01	79.3356410787063
1985-01-01	79.8264054763622
1986-01-01	78.6040899685925
1987-01-01	77.7754140707422
1988-01-01	77.2228776041164
1989-01-01	76.3833647253287
1990-01-01	75.1556848539827
1991-01-01	74.6288706533885
1992-01-01	74.7380455695400
1993-01-01	73.7906941882334
1994-01-01	72.3277735223278
1995-01-01	71.4937653230926
1996-01-01	69.1606531258442
1997-01-01	68.8091578463224
1998-01-01	67.7188343377556
1999-01-01	67.6155438535125
2000-01-01	64.6666536862586
2001-01-01	62.9021644042616
2002-01-01	60.9447273152185
2003-01-01	59.1831150178460
2004-01-01	57.5891684142542
2005-01-01	55.6070869044612
2006-01-01	52.7830387764362
2007-01-01	51.4469505868382
2008-01-01	49.9121105709270
2009-01-01	47.1274763146869
2010-01-01	45.8567452403661
2011-01-01	45.0267569261732
2012-01-01	44.3398634639192
2013-01-01	44.2116080414888
2014-01-01	43.8306552220130
2015-01-01	42.7350174000210
2016-01-01	41.1757409019607
2017-01-01	39.9070629739304