A summary of the analysis can be seen in the output tab at the bottom of the screen. "ACU-%" is the accumulated modal participation factor. Modal effective mass and participation factor are relative measurement to the total vibration. For example, if the "ACU-%" is 99% in the first five modes, it implies the first five modes are dominant modes, and the rest of the modes can often be ignored. Modal effective mass and participation factors are often used in constraint vibration such as Dynamic Design Analysis Method (DDAM).