Values come straight from the game and mod database files (base game, three expansions, then Grimarillion overrides). Ranks above a skill's max can only be reached with +skill bonuses from gear. Flat values that don't change with rank are shown in grey. Damage over time is shown as the total over its duration, as the in-game tooltip does. Flat damage is the skill's base value; your in-game tooltip shows it higher because it adds your character's % bonuses for that damage type.