Year	Percent
1991-01-01	42.5580036663368
1992-01-01	42.4322836850905
1993-01-01	42.2261720335897
1994-01-01	42.1335740602447
1995-01-01	41.6987591090266
1996-01-01	42.1432434003773
1997-01-01	42.1953231831870
1998-01-01	41.7735981629186
1999-01-01	42.2760138294645
2000-01-01	41.9357396837135
2001-01-01	41.7099828387444
2002-01-01	41.4203965919193
2003-01-01	41.5769653633484
2004-01-01	42.1086304979873
2005-01-01	42.3357537880510
2006-01-01	42.8762958743032
2007-01-01	43.4581105490418
2008-01-01	43.8299291648950
2009-01-01	43.9865968948549
2010-01-01	43.9285570405533
2011-01-01	43.7424796338029
2012-01-01	43.7508507561440
2013-01-01	44.0130252952332
2014-01-01	43.7034489647277
2015-01-01	43.6554657262617
2016-01-01	43.7315582758107
2017-01-01	43.7946650483198