It takes 10 minutes for a chest to respawn. On average you get two crowns from a chest. (1-4 Crowns per chest) I opened 100 chests and I got 55 items (Arrows, bait, equipables (excluding weapons) , weapons) 53 crowns means amount of times not the total amount of crowns.
Basically:
≈ 8% chance to get double items
≈ 14% chance of clothes and amulets
≈ 26% chance of arrows
≈ 14% chance of bait
≈ 1% chance to get a weapon
–
≈ 47% chance of Items
≈ 53% chance of Crowns
Though everything is based of what I got in 100 chests.
I suggest doing this another 100 times a few more times and average your results between them for somewhat more accurate results. Not saying your results aren’t accurate just saying further testing would make them more accurate.