Rigol 2072 Duty Cycle Measurement Question

[Electro Fan]

Most of the time Duty Cycle is displayed as a percentage such as 50.0%.  Sometimes it is displayed as something such as 288.8m%; occasionally it toggles back and for between the xx.x% format and the xxx.xm% format.  Any idea what the xxx.xm% format means?  Thx, EF

[andtfoot]

I'd say is m = milli, so 288.8m% would be 0.2888%.