Year	Percent
1991-01-01	23.0590000152588
1992-01-01	23.0739994049072
1993-01-01	23.0620002746582
1994-01-01	23.0189990997314
1995-01-01	22.6690006256104
1996-01-01	36.1059989929199
1997-01-01	30.8780002593994
1998-01-01	22.0879993438721
1999-01-01	18.2320003509521
2000-01-01	19.6389999389648
2001-01-01	35.3810005187988
2002-01-01	42.5660018920898
2003-01-01	38.2960014343262
2004-01-01	39.7669982910156
2005-01-01	36.2649993896484
2006-01-01	35.6269989013672
2007-01-01	35.0960006713867
2008-01-01	40.7340011596680
2009-01-01	38.8370018005371
2010-01-01	38.7480010986328
2011-01-01	35.6180000305176
2012-01-01	38.6699981689453
2013-01-01	40.7879981994629
2014-01-01	43.3709983825684
2015-01-01	40.3419990539551
2016-01-01	41.5719985961914
2017-01-01	43.0239982604980