What age definition is used for mortality rates in the CMI tables?
The CMI uses the standard definition of q(x) in its tables; that is q(x) is the probability that a life aged exactly x will die in the next year i.e. before attaining exact age x+1. Similarly, q(x+.5) is applicable from exact age x+.5 to exact age x+1.5. This notation is described in most standard texts on the subject, e.g. page 8 of Life Contingencies by Alistair Neill. For the avoidance of doubt, the age definition in the tables is not next, nearest or last but exact.
