Premise: This estimate of 10 GWe of scrubber retrofits by 2005 was determined from the difference between the boilermaker labor hours available from the boilermaker membership working in the electric utility industry and the labor hours needed to complete control technology retrofits and other electric utility projects.

Hypothesis: The estimate for the scrubber retrofits was made with the difference in labor hours available and labor hours needed.
Relation: entailment