Excel 2010: I need a formula for asking discount from my supplier

Hi friends!
I have received price list from my supplier in Germany, the price quoted in Euro, I have found some items prices are increased significantly so i would like to ask discount to cover my target price. please find below details i provided for find out the formula;

A2= My Supplier price in Euro €13.93
B2= My landed cost in BHD 7.370 (Bahrain dinar)
C2= My target price to get from my supplier in Euro €8.80
D2= My target landed cost in BHD 4.224
E2= ??? (need formula to find out the discount percentage from A1 to C1 also the discount percentage should be tally with my target price in BHD 4.224)

Please find attach the file for your easy reference.

Can anyone provide me the formula?

Thanks and best regards,
Alagarsamy