Average Wrap Calculation not always reading correctly

Version 1
    This document was generated from CDN thread

    Created by: Sarah Barnes on 21-01-2013 06:27:31 AM
    I have created an Average Wrap calculation within the SQL  AvgWrapAHT = ISNULL(AgentSkillGroup.WrapTime / AgentSkillGroup.CallsHandled, 0),
    I have also created Average Hold & Average Hanlded Talk Time based on the same type of calculation.
    in 90% of the agents, these 3 calculations added together equate to the AHT cisco calcultaion
    AHT = ISNULL(AgentSkillGroup.HandledCallsTime / AgentSkillGroup.CallsHandled, 0),
     
    Does anyone have any idea why 10% of the agents are shoing different?
     
    Once again all help gratefully received.
     
    Cheers Sarah