From Fallen London Wiki

The distribution graph also appears to be no longer accurate. I finished out the Bohemian Sculptress' dream with the "A Saint of your making", with Intensity 8 and Duration 20, and it gave me an overall Intensity of 9, 1 Verse of Counter-Creed, 2 Apostate's Psalms, and 1 Palimpsest Scrap (instead of the 3 expected from the current listed distributions).

Additionally, is there a set formula for the bonus from Duration, or is it randomly chosen from [0 - (1/4 Duration)]?