@nifiii is absolutely correct.
Take it on some long route, drive around 100-120 kmph, reset the average meter and then note average.
Remember, in short routes, stop and go traffic, rush, etc. fuel efficiency drops to a miserable figure.
Also try to drive gently and with a soft foot.
Btw, what is your odometer reading and model year?
Did you clean the plugs and got throttle body serviced?