the CI is the price of one minute of flight (fuel cost excluded) in terms of kilograms of fuel.
If your airline has very very well paid pilots, cabin crew and employees, and has very high costs for maintenance and others, and fuel price in your home base is very very cheap, then your CI will be high.
If your airline pays peanuts to the employees, and is low cost, and maitenance is cheap, and fuel is very very expensive, then the CI will be low.
The guys in the first airline "we few, we lucky few..." will cruise at .79 or .80. The unlucky ones will cruise at .77, 76...
But don't worry too much about that. Knowing what is the real CI of an airline for each particular route is so so difficult, that most of them just stick to a CI for years until nobody dares to change it, as if it was some ancient god.