Verb agreement with percentages [duplicate]
Over 50 per cent of our materials come / comes from local suppliers.
Your inclination is well-founded.
The noun "percent" (or "per cent") belongs with the number-transparent nouns: the kind where the verb agrees not with the head noun but with the noun that is complement of the preposition "of".
Here, the complement is the plural NP "our materials", so it follows that the verb should be the plural form "come".
Note that where the complement of "of" is a collective noun, singular agreement can be overriden: One percent of the electorate was/were unaware of the issue.