Active editors (blue) refers to the number of user accounts making at least 5 edits in that month
Retention rate (red) refers to the percentage of editors who first edited in the specified month and also went on to make at least one edit 12 months later.
The stats reported here were constructed based on the 2015-04-03 database dump of the English Wikipedia and processed in a way so as to mimic the original analysis but without using any of the original software. In order to replicate the prior image, only registered users that have made at least 10 lifetime edits were included. This has the effect of decreasing the number of active accounts and increasing the apparent retention rate relative to samples that don't have that restriction.