Help! Billboard income ranges?? -- Denver

[Niles Emerick]

I have a property with a full size billboard in the city of Denver and am looking to renegotiate the terms with the billboard company. This will be my first billboard negotiation and I am hoping to find some information as to average rents per year/mo. and any other terms I should consider before I enter into these negotiations.

It is currently rented at $1500/yr. which seems extremely low to me. Anyone with experience and perspective, or a good resource?

Thanks!

Niles