Not just for this, but almost everything.
The Paredo Time Principle?
The Pareto principle (also known as the 80–20 rule, the law of the vital few, and the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes.
http://en.wikipedia.org/wiki/Pareto_principle
The Pareto principle (also known as the 80–20 rule, the law of the vital few, and the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes.
http://en.wikipedia.org/wiki/Pareto_principle