LogFAQs > #971107720

There was a gap of 17 years from when Bilbo left to when Frodo left. He pretty much aged as normal.

When we see him next at the grey havens, Sam had kids already so must have been at least a few years from when they got back (maybe 10 as a rough estimate?)

Gollum also had centuries to be corrupted by the ring. By the time he lost it he was already fully under its influence. He also used it far more than Bilbo.