2008-12-10   6.310
2009-01-25   6.750
2009-11-06   6.400
2009-11-20   6.960
2010-02-17   6.650
2010-03-31   6.720
2010-12-14   6.720
2012-01-11   6.390
2012-11-20   6.550
2013-02-17   6.800
2013-03-06   6.660
2013-03-14   6.900
2013-11-28   6.610
2014-12-31   6.640
2015-01-11   6.900
2015-12-01   6.550
2016-02-10   6.920
2017-02-13   6.840