[jfoley]

I believe the bottom graph indicates levels as measured one year ago.

EDIT: Looks like data from a little over a year ago- The date range in the screenshot is from Dec 4th to 5th 2010.

[patio11]

The Japanese reads "For comparison: data from December 2010."

Other text: "100 CPM is equivalent to exposure of 1 micro-sievert per hour". Or, approximately one tenth your rate of exposure when flying commercial.