2008-03-31   -4.146
2008-04-28   -4.002
2009-04-21   -3.790
2009-05-06   -3.813
2010-04-01   -4.259
2010-09-30   -4.210
2011-03-26   -3.940
2013-03-13   -4.028
2014-03-17   -3.885
2014-05-28   -4.040
2014-09-22   -4.086
2015-06-25   -4.141
2015-07-25   -4.054
2017-02-13   -3.971
2017-05-20   -3.822