Multiplayer stats

[oraq]

Can someone tell me what the 'stars' in the after match report represent?
I am confused as to what they are for and why they differ wildly match to match.
For example, i play strike a lot with Blenheim yet one match i won but only managed to bomb opposition to half points and somehow got about 25-27 'stars'.
Yet another match i annihilated the opposition into minus points, yet only got about 5 'stars'
Assuming (i am prob wrong) these stars represent mission effienciency, and the job of a bomber is to bomb... then the second mission i referred to i expected more..........

Please explain.