I answered their questions 'to the best of my knowledge'. [=I gave the best answers I could based on what I knew, but I might have answered differently if I had known something else]
No one arrived late 'to my knowledge'. [=I am not aware that anyone arrived late, but it is possible that someone arrived late and I don't know about it]
They went on vacation, 'safe in the knowledge' that the farm would be well cared for while they were away.
(..) laid a finger on Andy again. And Bogs would never walk again. They transferred him to a minimum-security hospital upstate. To my knowledge, he lived out the rest of his days... ...drinking his food through a straw. Andy could use a nice welcome back when he gets out of the infirmary. (..)1994 The Shawshank Redemption