Consumption D5 very high

Hello Volvo driver I would be interested in your consumption on shorter routes, so no tank filling with motorway.Drive mostly on the day about 18km to work, of which 50% are rural road and 50% city(no stop and go or Kavaliestart).My D5 is now 1 year old and started with 8,4l on 100km.Today with a consumption of good min.9.3L on the same route. Thus, every two months increased by 0.2l. Even with motorway ride of 500km (120km/h cozy) and 300km above described track still at least 8,2L consumption.Bein meine erwesen Dieselfahrzeuge (were not Volvo) always driven at the below stated consumption limit.My friend is at a loss and changed the AGR,was in error memory, but did not bring anything.Has someone similar experiences. mfg Werner