Does anybody know much about the conversion rates from 3P to 2P....

Does anybody know much about the conversion rates from 3P to 2P. Is there a general rule of thumb as to how many Pj of 3P is usually certified into 2P? Just doing some quick calculation using other CSG companies and i have come up with a ratio of 2.52 based on 7 companies. Applying that to PES with 1241 3P they should be able to certify 492 2P as opposed to the 300 the company is targeting. I dont know if it is correct to apply ratios like that so if anybody is an expert on CSG certification please 'enlighten' me

sloeb