How to create a poll in a SMF forum where mulitple votes are allowed for the same answer?

I am building a forum for a fellowship that helps animal charities.

As a means to make it easy to see which charities is not getting as much help as the other I set up a poll with answers that are the charity names.

This is how it needs to work:

Lets say I paint a painting and it sells to benefit Old Dog Haven I vote for Old dog haven. All the other members do the same when they make a sale to support one of the charities. This way since the results are always visible we can see which charity needs support.

Here is the problem- lets say the next week I paint another painting that sells for Old Dog Haven. The poll as it stands right now will not allow me to vote more than once for each answer.
(It will let me vote once for each charity but not more than once)

Does anyone know how to override this so that each member can add to the votes multiple times for each charity?

I have researched and posted in SMF forums with no luck yet. Any help offered will be greatly appreciated.