Year	Percent of Total
1990-01-01	9.58597657368807
1991-01-01	9.94559895765266
1992-01-01	10.32082092653060
1993-01-01	10.70233495726730
1994-01-01	11.07782017561160
1995-01-01	11.44083551165320
1996-01-01	11.92165069961910
1997-01-01	12.37240495194250
1998-01-01	12.79208625872250
1999-01-01	13.18033838331220
2000-01-01	13.53670021391050
2001-01-01	13.84081743740690
2002-01-01	14.11142551807200
2003-01-01	14.33797466136520
2004-01-01	14.49869593295470
2005-01-01	14.58352731083910
2006-01-01	14.60371519964100
2007-01-01	14.55271874309680
2008-01-01	14.48035024141850
2009-01-01	14.45949565548150
2010-01-01	14.53579492422570
2011-01-01	14.77814694789020
2012-01-01	15.08844941556220
2013-01-01	15.45695927732680
2014-01-01	15.86694087551740
2015-01-01	16.30528014027350
2016-01-01	16.82354916614730
2017-01-01	17.36590807380720