A finding which states that twins should occur naturally once in 90 live births, triplets once in 8,100 live births, quadruplets once in 729, 000 live births, and quintuplets once in 65, 610, 000 live births.
A law stating that twins occur once in 80 pregnancies, triplets once in 6400 (802) pregnancies, quadruplets once in 512,000 (803) pregnancies.