The tutor reports an interesting statistic.
In 2013, the world population was approximately 7.07 billion. At the same time, people aged ≥ 100 numbered about 450 thousand. Those figures suggest that a completely random person on Earth has probability 450 000/7 070 000 000 = 0.000064 of reaching age 100 or greater.
The probability equates to about 64 in one million.
Oracle Tutoring by Jack and Diane, Campbell River, BC.