2008-12-10   6.830
2009-01-25   6.440
2009-11-06   6.360
2009-11-20   7.070
2010-02-17   7.210
2010-03-31   6.240
2010-12-14   6.550
2012-01-11   5.560
2012-11-20   6.640
2013-02-17   6.840
2013-03-06   6.440
2013-03-14   6.710
2013-11-28   6.300
2014-12-31   6.880
2015-01-11   6.640
2015-12-01   5.920
2016-02-10   5.770
2017-02-13   5.820