There really is no simple answer to your question.

Airlines use sophisticated yield management systems which take account of both historic trends and forward booking patterns, but the reality is that no two flights are ever the same. And that's not just because load factors will vary by day/season (and sometimes dramatically so) but because revenue profiles will be made up of so many different fare types on any given sector : full fare tickets, FIT fares, mileage redemptions, staff duty travel, annual leave tickets, staff family concessions, AD & ID tickets, route incentive deals, and all manner of other concessionary or 'guest' travel (eg press/industry journos etc etc ...... the list is almost endless ....).

And once you've taken account of all that, you'll need to get a handle on EK internal costs (good luck with finding out such stuff !!) not to mention airport fees etc etc etc .....