[agurk]

Thank you for doing the research to find the numbers for this.

I think it's worth adding, as is reflected by your B767 ground movement figure that all jet engines are very inefficient at low power outputs, not just the Concorde's/supersonic aircraft. This is as a large amount of energy is needed to create sufficient compression to allow them to function.

Finding ways to minimize the amount of time spent in these states has been the industry's approach to date.