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 Dahtekkes.
Herblore 99 → 106, 12.9m XP
Summoning 77 → 96, 8.1m XPWeakest area: Summoning. Summoning 77 → 96, 8.1m XP. Quests need a public profile, so the quest checks are left out of the score.