Year	Percent
1997-01-01	2.10537
1998-01-01	1.93672
1999-01-01	4.14203
2000-01-01	5.54535
2001-01-01	13.04180
2002-01-01	19.87480
2003-01-01	22.24550
2004-01-01	29.38770
2005-01-01	29.24760
2006-01-01	33.49200
2007-01-01	36.41320
2008-01-01	36.70230
2009-01-01	38.10720
2010-01-01	39.97280
2011-01-01	43.19150
2012-01-01	46.94680
2013-01-01	48.66440
2014-01-01	51.17840
2015-01-01	52.42200
2016-01-01	53.82740