Skoda Fabia Mk 2 1.6 105 TDI 90k oil consumption normal?

Hello,

Our 14 plate (Mar 14) Fabia diesel (105bhp) has about 91k miles on the clock and appears to be consuming a bit of oil. I noticed this when I checked just before the MOT end of Feb and noticed it was right on the low borderline. It had previoulsy had an oil change in November at about 85k miles and is now on 91k. I topped it up for the MOT which it passed but I think it has gone down slightly in the 500 or so miles since. What would be a reasonable amount of oil usage for a car of this age and mileage and what would be an unreasonable amount? I accept some oil consumption but want to know if something more serious is going on.

As an aside we use this car mainly for long drives on motorways and A roads and rarely around town on small, cold journeys.

Thanks for your input.