To the best of my knowledge JHU does not provide the stats necessary to inform such a decision. Even data available on financial aid for international students would be misleading since international students are a very diverse group that are highly variable year to year. As an Iranian applicant you would probably not be represented well by the available data even if you could find it. You can try contacting the financial aid office with detailed questions, but I’m sure they will not provide this level of detailed stats, and they will simply encourage you to apply. If you are considering applying RD then I wouldn’t be concerned since (beyond the time and application fee) there isn’t much drawback in learning if you receive financial aid, and, if so, how much. If you’re applying ED then there is the risk that you might be coerced into attending a school with an unfavorable financial aid package, so maybe you should just apply RD. Or, take the risk and hope that even if you are accepted ED, hate the financial aid and refuse, there are limited repercussions in your case as an Iranian applicant (as if we need more drama in the international relationship between our countries).
I’m sure you have a good idea if you would be a competitive applicant or not. You can post your stats if you feel that will help, but beyond standardized test scores I wouldn’t know how to fairly compare an Iranian GPA, ECs, etc. with U.S. applicants. Even if your scores are not competitive, there are many additional factors to consider in your case that could compensate for this. It’s hard enough comparing U.S. applicants with each other, attempting to go on an international scale is well beyond my comfort zone and is exactly why there are whole committees of trained professionals that do this for a living.