How to get accurate prior rental income numbers?

[Braden Hobbs]

I'm in process of making first few offers and I'm trying to do my due diligence and discover true rental income numbers from seller. However, when I've asked to see these numbers before making an offer the seller/agent seem taken aback. Is there a better way to ask? I've never had an issue asking my sellers to provide rent rolls, and they usually understand why it's being asked for.