Year	Percent
1991-01-01	2.62899994850159
1992-01-01	3.69899988174438
1993-01-01	4.33099985122681
1994-01-01	7.89599990844727
1995-01-01	7.28200006484985
1996-01-01	9.27499961853027
1997-01-01	7.28000020980835
1998-01-01	6.40899991989136
1999-01-01	6.77099990844727
2000-01-01	6.38999986648560
2001-01-01	6.32299995422363
2002-01-01	6.92899990081787
2003-01-01	10.89099979400630
2004-01-01	16.79000091552730
2005-01-01	13.64500045776370
2006-01-01	16.05400085449220
2007-01-01	15.02700042724610
2008-01-01	17.59099960327150
2009-01-01	17.01499938964840
2010-01-01	14.14400005340580
2011-01-01	16.70000076293950
2012-01-01	18.53100013732910
2013-01-01	15.36499977111820
2014-01-01	22.00699996948240
2015-01-01	17.23800086975100
2016-01-01	18.70400047302250
2017-01-01	15.22999954223630