Air carrier First Officer reported high engine vibration indication during cruise. Flight crew diverted.

Narrative

On Flight ABCD from ZZZ1 to ZZZZ (Day 0) we experienced N1 Fan Vibrations outside of the normal range (4.1) in cruise at FL370. After running the QRH procedure and descending to FL330 the issue was not resolved. We were advised my the company to divert to ZZZ with no further complications. Cause: I am unaware of the cause of the N1 Fan vibration; as we were not in icing conditions. The Logbook noted that this had been an issue on past flights; and I had done a vibration check in ZZZ2 earlier that day with a mechanic.