A low figure like that is not uncommon, how are you using the car? Short journeys in town will ruin consumption.
With a car of that age and mileage the first thing I would do is ensure that you are using decent fuel not some of the unbranded cheap stuff that is available these days.
Get some injector cleaner, put couple of doses in the tank and fill up then give the car a good run with plenty of full throttle revs. That'll clean out the crud that may have accumulated during its life and spoiling the engine performance.
Vic.