Live comparison: Don't understand Power and Energy calculation?

Hi

If I compare the Live data of two systems, the last two rows of the comparison are the difference of Power and Energy in percent. But I don’t understand how this two values are calculated?

What ever I try to calculate, I get differnt values.

Look at the image, the yello marked row at 19:40h:
1st System Power = 692W, 2nd System Power = 200W, calculated difference = 37.5% less ?
1st System Energy = 39,517kWh, 2nd Sysetm Energy = 43.700kWh, calculated difference = 2.6% less ?

How do they get this percentage values?

Regards

Addendum:

I have now understood how the calculation is carried out; the two percentage values (Power and Energy) do take the unequal panel size / power into account and do normalize the result.

So the result represents the performance values as if both systems had the same panel Wp performance (kWh / kW)

Thanks anyway
Roman