What is the liability for having a trampoline in my yard and if someone gets hurt while playing on it?

If you have a trampoline in your yard you are liable for anyone who gets hurt on it, Even if kids come over when you are not home and get hurt, they can sue you.

What is the liability for having a trampoline in my yard and if someone gets hurt while playing on it?
My homeowners insurance company said they do not insure homeowners who have trampolines because of the liability it imposes