Is there any case law where the award of global damages is based on a calculation of global average damages?

See also judgment of Dickson J. in Lewis v. Todd, supra, at pp. 708-709: … the award of damages is not simply an exercise in mathematics which a judge indulges in, leading to a "correct" global figure. The evidence of actuaries and economists is of value in arriving at a fair and just result. That evidence is of increasing importance as the niggardly approach sometimes noted in the past is abandoned, and greater amounts are awarded, in my view properly, in cases of severe personal injury or death. If the courts are to apply basic principles of the law of damages and seek to achieve a reasonable approximation to pecuniary restitutio in integrum expert assistance is vital. But the trial judge, who is required to make the decision, must be accorded a large measure of freedom in dealing with the evidence presented by the experts. If the figures lead to an award which in all the circumstances seems to the judge to be inordinately high it is his duty, as I conceive it, to adjust those figures downward; and in like manner to adjust them upward if they lead to what seems to be an unusually low award.