In an earlier draft, I called IEA an organization of oil consuming nations. I later changed this to an organization of oil importing nations.

According to Rune Likvern, Norway is only an associate member of the IEA because it is oil exporter. It is listed as member of OECD, however. This collection of IEA graphs shows crude oil imports by OECD country.

Japan uses a disproportionate amount of oil, because natural gas can only be imported as LNG (which is very expensive) and it has little or no fossil fuels of its own (except a little offshore). A comparison of the scales on the graphs shows that the US imports about 10.5 million barrels a day and Japan about 4 million barrels a day. Other countries import much less.

I don't know why Japan has such a high assessment. It seems out of line with its oil imports or use.

Japan used to pay more towards various international 'good causes' as a compensation for it's inability to contribute militarily due to it's constitution limitations.

The habit has somewhat fallen by the wayside, as to a degree has observation of the constitution.