2008-03-31   6.520
2008-04-28   7.020
2009-04-21   5.950
2009-05-06   5.910
2010-04-01   8.490
2010-09-30   9.530
2011-03-26   5.560
2013-03-13   7.300
2014-03-17   7.890
2014-09-22   7.760
2015-06-24   6.220
2015-07-24   6.500
2017-02-13   7.210
2017-05-20   6.250