Mortality Rate as a Function of Age

The first three figures show estimates of the instantaneous mortality rate, which is the expected rate at which people die per unit of time (here the year) at each precise age, relative to the surviving population at that age. If this is called M, and if it were constant, then the probability that a particular individual will die within one time unit (year) would be 1 – exp(–M), the remaining life expectancy (mean life) would be 1/M, and the half-life would be ln(2)/M. Since M actually varies with age, only the first of these relationships is reasonably accurate in general, and only if M is taken to be the value in the middle of the one-year (or other) span.