Eeeer, it's not $240,000 'profit' but Gross Income. You will never find out what it costs to operate the sector. Part of that is that each sector has to carry not just the cost of it's own operation but a percentage of the overall cost of running an airline. (Think about insurance for a moment)
Further, they have to allow for the cost of flights that do not run with high loads. They are looking at operations across the whole year. Since each flight is priced to maximise it's income (naturally) they could operate ten sectors in 2016 and the same ten sectors (with the same aricraft and identical loads) in 2017 and make less money.