gttr application- breakdown of qualifications

hey people im really really stuck with my gttr application....ive finally done my personal statement but now im all confused about the breakdown of the degree part. im doing a degre in childhood studies and it has about 20 modules in it. iv separated the main modules to the other modules but i dont really get the whole percentage part, if i put a percentage for each of them then it works out like 4% or 7% and it dont seem right.....im probably sounding really daft but could anyone help me please?

thank you in advance x x