Year	Percent
1991-01-01	2.93799996376038
1992-01-01	2.92499995231628
1993-01-01	2.91400003433228
1994-01-01	2.91700005531311
1995-01-01	2.92000007629395
1996-01-01	2.92300009727478
1997-01-01	2.93799996376038
1998-01-01	2.95399999618530
1999-01-01	2.94499993324280
2000-01-01	2.94600009918213
2001-01-01	2.94400000572205
2002-01-01	2.94099998474121
2003-01-01	2.93499994277954
2004-01-01	2.92799997329712
2005-01-01	2.91899991035461
2006-01-01	2.90899991989136
2007-01-01	2.89100003242493
2008-01-01	2.88000011444092
2009-01-01	2.84400010108948
2010-01-01	2.81500005722046
2011-01-01	2.78399991989136
2012-01-01	2.75900006294250
2013-01-01	2.73699998855591
2014-01-01	2.91899991035461
2015-01-01	2.90499997138977
2016-01-01	2.95799994468689
2017-01-01	2.89899992942810