80/20 PRINCIPLE

V. Pareto was an economist who lived from 1848 to 1923. 
" Pareto' s Law" or the  "Pareto Distribution" in the last decade popularly called the 
" 80/20 Principle".
This principle shows that 80% of the wealth and income was produced and possessed by 20% of the population.
Pareto's Law can be summarized as follows:  80% of the outputs result from 20% of the inputs.
Alternative ways to phrase this include:
80 % of the results come from 20% of the effort and time.
80 % of the company profits come from 20% of the products and customers. 
80 % of all stock market gains are realized by 20% of the investors.
20 %  of customers are consuming 80% of work time.
The list is infinitely long and diverse.