Consulting the Codex…
RS3 · Skills · Activities · Quests
The Codex keeps its readings for 400 days, so you can go back that far, to the first day it read Chank Chi.
Herblore 85 → 96, 6.2m XP
Prayer 84 → 95, 5.7m XP
Summoning 77 → 96, 8.2m XPWeakest area: Potions. Herblore 85 → 96, 6.2m XP. Quests need a public profile, so the quest checks are left out of the score.