Shaman · Elemental Combat · tier 1 · from level 10

Concussion

+14.7 Earth Shock

5/5 · level 60 · per cast · and 2 more

Concussion 12345

Rank 5/5

Increases the damage done by your Lightning Bolt, Chain Lightning, and Earth Shock spells by 5%.

Earth Shock +5.0% +14.7 Lightning Bolt +5.0% +9.8 Chain Lightning +5.0% +6.2

Averages, counting crits and misses, for a level 60 Shaman with a typical weapon and no other gear or buffs, against a target your level. Worked out from the game's own data, the same way as the Foresight addon.