I go by 13% by day 18, then raise the humidity during lockdown. Can't weigh after lockdown and higher humidity slows down the water loss so after lockdown the weight loss slows down. How much, I don't know but that works for me.
This says they weigh 60-65 g each.
How much did they weigh on average a piece when you first got them?
How much did they weigh on average a piece on day 11?