Each region of the world is assigned a colour (North America – brown; Oceania – dark blue; Europe – light blue; Asia – grey; Latin America – yellow; Middle East – green, and Sub-Saharan Africa – red). The vertical axis focuses on the proportion of edits to articles in the region that come from that region [“received edits”] and the horizontal axis focuses on the proportion of a region’s committed edits that stay within that region [“committed edits”]. (note that The data shows anonymous edits only (+), registered edits only (×) and both edit types combined (●))
Source : The Connectivity, Inclusion, and Inequality Group
Oxford Internet Institute, University of Oxford.
http://cii.oii.ox.ac.uk/2014/12/04/visualising-the-locality-of-participation-and-voice-on-wikipedia/