Year	Percent
1986-01-01	80.8119903062800
1987-01-01	79.4586373982419
1988-01-01	75.3159569920773
1989-01-01	73.7653587117045
1990-01-01	72.5245356676530
1991-01-01	71.4028695800246
1992-01-01	69.6229212132618
1993-01-01	68.7846420125675
1994-01-01	70.0400597744388
1995-01-01	71.2251193862890
1996-01-01	70.5668355332193
1997-01-01	69.6734953440437
1998-01-01	67.8661333861786
1999-01-01	66.6509320465881
2000-01-01	65.8201559798132
2001-01-01	66.1830767982351
2002-01-01	66.7345567006299
2003-01-01	65.2892191626078
2004-01-01	65.6679487934456
2005-01-01	65.5299387342230
2006-01-01	67.3110381423674
2007-01-01	66.9870875330585
2008-01-01	65.4944035084705
2009-01-01	63.3204637980052
2010-01-01	60.8853615024586
2011-01-01	60.9911130137347
2012-01-01	60.4626213595993
2013-01-01	59.6829535505896
2014-01-01	62.2430958497711
2015-01-01	63.6934337555329
2016-01-01	64.9468662963013
2017-01-01	65.4135783102936