Air Dose Rate Results of the Sixth Airborne Monitoring Survey and Airborne Monitoring Survey Outside 80 km from the Fukushima Dai-ichi NPP ( Decay correction: December 28, 2012 ) (Whole area) Air Dose Rate Results of the Sixth Airborne Monitoring Survey and Airborne Monitoring Survey Outside 80 km from the Fukushima Dai-ichi NPP ( Decay correction: December 28, 2012 ) (Whole area)