18v AC/5v DC Power Supply

[Hero999]

Most 120V countries work from a split phase a supply so larger loads can be run off 240V, and 415V three phase.

 

[Hayato]

I think a LOT depends what China uses?

Interesting breakdown by countries, but as suggested population would be helpful as well?

A quick Wikipedia https://en.wikipedia.org/wiki/List_of_countries_with_mains_power_plugs%2C_voltages_and_frequencies makes it quite clear with a nice coloured map!.

Nice graph, Nigel.
It was a joke, but I could have done some researchs on the subject before.

 

[audioguru]

Trillions of Chinese people have never heard of electricity.