During law school, I learned of the "80-20 rule," which holds that 80% of effects are due to 20% of causes. For example, 20% of students are usually responsible for 80% of extracurricular activities - at dinner one night, I was part of a random conversation among friends which concluded with our dividing up the leadership positions of every conservative group at the school for the next year.
I thought being part of the 20% was notable, but Ethiopia's Catholic population puts me to shame. A Q&A with Bishop Saldarriaga, apostolic vicar of Soddo-Hosanna, mentions the following statistic:
Although Catholics number less than 1% of the population, the Catholic Church runs more than 90% of the social programs in Ethiopia.
An "80-20 rule" is impressive, but a "90-1 rule" is uncanny.