I am a excel newbie and I need some help with a formula.

I want to find the percentage of orders delayed from a list of orders, and I want them to be divided by suppliers so I can find the percentage of orders delayed from each supplier. I thought I can use the list of orders since it has a column where you can find a time of how much each order was delayed, if it says ,"", there was no delay.

My formula from the column next to the one I am working on right now where I find out the average delay divided by supplier is the following:

=LOOKUP(9,99999999999999E+307;CHOOSE({1;2};0;AVERAGE(IF('Order statistics'!$B$2:$B$10=A8;'Order statistics'!$D$2:$D$10))))

I understand that my explanation is a bit complicated but if somebody could give me a hint to work from I would bu thankful.

I was thinking that I need to find all ,"", compare those to the orders that was delayed per each supplier and thereby find the percentage, but how to do this...

Thanks

David