... precise dates of each death, the usual (“actuarial”) convention is that about half the deaths in a year take place in each half of the year. So, if there are d deaths in a year in a group whose ... Conditional expectation of life, given achieving a certain age, can also be calculated by summing the years of life at that age and later, and dividing by the number achieving that age. Some example ... has a distribution of ages, and expectation of remaining life is age-dependent. Therefore, in quantification, it is an advantage to arrange the calculations in a two-dimensional array such as...