That census indicated that only 12 of the 1,178 radiotelephone firms had 1,000 or more employees.
That census of radiotelephone firms was taken 40 years ago.
mnli hypothesis: That census of radiotelephone firms was taken 40 years ago. premise: That census indicated that only 12 of the 1,178 radiotelephone firms had 1,000 or more employees.