% Rool-Upon another sheet


I have created a construction schedule where i have many lines of of tasks that apply in a mixed format to different subcontractors.  Each task has it own % value.  I have created another sheet where I have listed the Subcontractors and am trying to roll up the %of every line (associated with a specific subcontractor into a single % on this sheet.  I have started off to with using the formula =SUM(COLLECT) and that seems to work, But i need the average not the sum.  I have tried =AVG(COLLECT), but with no luck.  Maybe I am not using the AVG correctly?

Any ideas?