Extra Credit Riddle

You should know the following data:
min #
QI
Median
Q3
max #
Also be able to interpret the data. example: If Sam weighs 70 lbs, what percent of his class weighs more than him?

This thing devours all,
Birds, beasts, trees, flowers,
Gnaws iron, bites steel,
Grinds hard stones to meal,
Slays kings, ruins towns,
And beats high mountains down.

What is it? Submit answer to me by support class.