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 slutty shrek.
Defence 84 → 90, 2.2m XP
Herblore 87 → 96, 5.4m XP
Prayer 82 → 95, 6.2m XP
Summoning 80 → 96, 7.5m XPWeakest area: Potions. Herblore 87 → 96, 5.4m XP. Quests need a public profile, so the quest checks are left out of the score.