sj = (1 − tdj) (1 − trj),
where tdj is the weighted proportion dying among those employed, unemployed, not in the labor force, and outside science (= edj, the proportions for all these groups being equal), and trj is the weighted proportion retiring among those in these groups who do not die. (These factors are specific by field and gender, but subscripts are not shown for that.) Then the immigrants entering in 1985-86 should be
Rj,1985.5 = Rj+8,1993 / sj-1 / sj-2 / sj-3 / sj-4 / sj-5 / sj-6 / sj-7 / /sj-8
The results of these calculations were converted to annual numbers, dividing each two-year period in two. Figures for the last period (1987-90) were divided by 3.5, on the assumption that the period is truncated because migration had to take place before the 1990 census. After averaging across periods, the distribution by age was smoothed using five-year moving averages.