How would I set up this math equation?

If there's 83 million people in Iran, and 36,000 annually are converting to Christianity, how long will it take Iran to become Christian?

How would I set that problem up, without having to keep adding 36,000 until I hit 83 million. And the number of times I have to add it, is the number of years it will take for Iran to become Christian.

There has to be a simpler way to this, because that's gonna take forever.
11 mo
I did it the hard way, and it is indeed 2305 but that seems impossible. That's why I thought I set the problem up wrong to begin with.
How would I set up this math equation?
4 Opinion