This table is a blend of Makeham's mortality law for ages 13 and above and
some ad hoc values for ages 0 to 12.
The parameters for Makeham's mortality law are
1000 * mu(x) = 0.7 + 0.05 * 10^(0.04 * x)
where mu(x) is the force of mortality.
The published Illustrative Life Table just shows ages 0 to 110 but in the
computing exercises of chapter 3 the authors explain that the table's age
range is from 0 to 140.