Year	Percent
1999-01-01	7.17515229610970
2000-01-01	5.75384758023378
2001-01-01	5.93711648065566
2002-01-01	6.66540615211844
2003-01-01	7.64771217853858
2004-01-01	7.49777372343776
2005-01-01	7.59647197371071
2006-01-01	7.39882911160476
2007-01-01	6.66098661462646
2008-01-01	6.46467764414020
2009-01-01	7.74346105421644
2010-01-01	8.10724709906799
2011-01-01	7.10741786388778
2012-01-01	7.64860318713159
2013-01-01	8.64143373733416
2014-01-01	9.01954304725880
2015-01-01	9.09328295484976
2016-01-01	8.06198472879828
2017-01-01	7.11471039531659