Clive Granger, "Can We Improve the Perceived Quality of Economic 
Forecasts", Journal of Applied Econometrics, Vol. 11, No. 5, 1996,
pp. 455-473.

There are no data other than those actually given in the paper, where the
source is also given. Specifically,

Table I is from 3DEC94 issue of the "Economist."

Table II are numbers extracted from a paper by Zarnowitz and Braun as
referenced in the paper.

Table III is extracted from the "National Institute of Economic Research
Review," January 1993.

Table IV is a summary of numbers published in "The Sunday Times" 18DEC1994.

The figures are just generated from the formula given and anyone with a
scanner can capture them.  The seeds for the random number generators used
to form the figures are, unfortunately, not available.