probably yr car 's engine is running slight rich for first few 100 km, before first tuneup,
-also in winter the choke keeps engine idling quite high.. when you drive less than keep yr car started,, you waste fuel but dont add in km driven ,, so av/km comes down.
couple of days back if my 1.6l car gave 10km on long run, so yr s on local drive giving 7 km seems ok to me.