Be sure that the "occupants load" number is a real, natural number (float), and not an integer; this is to be set in the property's value type.
Then everything should work fine.
I am not aware what the decimal seperator in Greece is. In Germany it's the comma.
You'll need to have the number in "occupancy type" be in the same format as per your PC's settings.
Lastly I would rather "ROUNDDOWN" than up... since rounding up makes no sense – if there is not enough space left you can't cram more people in, right?!