Year	Percent of Total
1990-01-01	2.13157991187515
1991-01-01	2.12942938706601
1992-01-01	2.12498114329565
1993-01-01	2.12160215912414
1994-01-01	2.12376423286279
1995-01-01	2.13389453803374
1996-01-01	2.14730348726172
1997-01-01	2.16801856540261
1998-01-01	2.19556766277915
1999-01-01	2.22989116007433
2000-01-01	2.27272092631451
2001-01-01	2.32398942198716
2002-01-01	2.37472140830157
2003-01-01	2.42452407129856
2004-01-01	2.47126103832689
2005-01-01	2.51285593246406
2006-01-01	2.56077355539748
2007-01-01	2.60201190554247
2008-01-01	2.64059745970599
2009-01-01	2.68187036632791
2010-01-01	2.72812060698889
2011-01-01	2.77656067721576
2012-01-01	2.82975860077859
2013-01-01	2.88351676828301
2014-01-01	2.93221375559926
2015-01-01	2.97382478311706
2016-01-01	3.01047549369039
2017-01-01	3.04310910345713