The correct Humidity for Hatching Aracuanas?

I am on day 12 of hatching a dozen Araucana eggs. This is my very first hatch. All are fertile according to my novice candling attempts I have followed my Hova incubator instructions on keeping the inner tray full of H20. The humidity has stayed around 40-42%. I was told 35-45% was good to day 18. However, I have also read its should be 50%. Can anyone please tell me what the humidity is really supposed to be at?

Thanks!
Tracy