Year	Ratio
1991-01-01	1.22417998313904
1996-01-01	1.18493998050690
1997-01-01	1.26512002944946
1998-01-01	1.26362001895905
1999-01-01	1.29987001419067
2000-01-01	1.32240998744965
2001-01-01	1.33047997951508
2002-01-01	1.36353003978729
2003-01-01	1.37987005710602
2004-01-01	1.38224005699158
2005-01-01	1.36952996253967
2006-01-01	1.37838995456696
2007-01-01	1.41945004463196
2008-01-01	1.47174000740051
2009-01-01	1.47202003002167
2010-01-01	1.44643998146057
2011-01-01	1.42692005634308
2012-01-01	1.39865994453430
2013-01-01	1.35322999954224
2014-01-01	1.33406996726990
2015-01-01	1.32626998424530
2016-01-01	1.29004001617432