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 RabidLlama.
Herblore 24 → 96, 9.7m XP
Prayer 46 → 95, 8.7m XP
Summoning 20 → 96, 9.7m XPWeakest area: Combat stats. Best style is Magic at 75, 90 is the usual bar. Quests need a public profile, so the quest checks are left out of the score.