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 lansterek.
Defence 86 → 90, 1.5m XP
Herblore 99 → 106, 12.8m XP
Summoning 93 → 96, 1.9m XPWeakest area: Summoning. Summoning 93 → 96, 1.9m XP. Quests need a public profile, so the quest checks are left out of the score.