The "Total" active editor numbers for past months on the report card [1] ("Active Wikimedia Editors for All Wikimedia Projects (5+ edits per month)") appear to have changed drastically at some point during the last few months.
Compare the table with the same numbers on stats.wikimedia.org [2] with its version as archived by the Internet Archive in May [3]. E.g.:
March 2013: 79346 (current) vs. 82105 (archived, also matches the number given in the monthly WMF report at the time [4])
February 2013: 75140 (current) vs. 77701 (archived)
...
June 2012: 77363 (current) vs. 78320 (archived)
...
Note that some shrinkage is expected because of page deletions, but these decreases are way too large to be explained by this effect.
Also, two smaller issues which might be related or not:
- For some reason, the source CSV file linked in the report card [5] contains empty columns for several other language projects (e.g. Chinese, Portuguese, and Polish Wikipedia, and Meta-Wiki), apart from those included in the charts.
- The June 2013 number for the Italian Wikipedia is currently missing from the report card chart ("NaN").
[1] http://reportcard.wmflabs.org/graphs/active_editors
[2] http://stats.wikimedia.org/EN/TablesWikimediaAllProjects.htm (Edits ≥ 5 column)
[3] http://web.archive.org/web/20130521103812/http://stats.wikimedia.org/EN/TablesWikimediaAllProjects.htm (Edits ≥ 5 column)
[4] https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Report,_April_2013#Data_and_Trends
[5] http://reportcard.wmflabs.org/data/datafiles/rc/rc_active_editors_count.csv
Version: unspecified
Severity: major