non-profit internship...where&how on resume

Hey guys, I have a quick resume/experience question. I am currently a grad student but I have been working with a non-profit 15hrs/wk throughout the summer. I have done some unrelated admin and fundraising stuff, however i am also in the middle of a financial/profitability analysis project.

Basically I am reorganizing their reports in order to calculate each events profitability. I have consolidated all the contributions/fundraising etc. to find the revenue related to each event, then I am finding the profitability by netting the direct and shared costs associated with the event and the non-profit. We are then going to create an "impact" rating system so that for each event we can plot profitability vs impact in order to clearly see which events are worthwhile and which need to be more efficient.

So my question is where/how should this go on my resume ? Is this something that should have a spot under work exp. and I need to spin what I am doing to be as relevant to banking as possible. Or should this be thrown at the bottom with volunteering activities, etc. with just one bullet point (or no bullets). I am unsure of the tradeoff between how much or how little I should emphasize this experience. Thanks in advance guys, any help is greatly appreciated.