Does anyone know of an addon that breaks down the amount of damage attributed to each players presence instead of only damage done by this player?

For instance: I join a group with my feral druid. The melee now has 5% increased crit and will therefore see and overall increase in DPS. This damage isn't caused by me personally, but it can certainly be attributed to my presence. Example: In this fight, your buffs increased the groups overall dps by 5000. .. or something.

Figure it'd be a nice way to see who really contributes what to a dungeon/raid group.