(Resending, got stuck in pending queue for size.)
Here's a trendline for about one month of usage.
The figure seems to be holding between 0.2% and 0.3% for that most recent 1-month period of available WML usage data in Wikipedia Zero.
Other content types are not counted in this WML percent; for example, the following hits on <language>.(m|zero).
wikipedia.org are excluded: JSON, XML, PNGs, icons, JavaScript and CSS. Furthermore, content served from domains such as
upload.wikimedia.org (media, including most article images) and
bits.wikimedia.org (frequently accessed core UX elements such as JavaScript, CSS, icons, etc.) is not part of the denominator.
The previous email referring to sub-0.1 percent WML /hit/ ratios on in-scope active carriers - for which I provided some rather basic analysis - holds. However, using the re-worked definition of WML percent described here there's a slightly higher skew.
In addition to the PDF trendline, a quick and dirty look at the 20140214 log for active operators shows the following rough layout.
Less than 0.5% WML
Overall traffic in this zone is 77.03% of the W0 traffic; average of 0.05% WML in-zone
Between 0.5% and 1.35% WML
Overall traffic in this zone is 22.73% of the W0 traffic; average of 1.08% WML in-zone
Between 1.35% and 4.9999999999% WML
Overall traffic in this zone is 0.22% of the W0 traffic, average of 2.07% WML in-zone;
5% and higher WML
Overall traffic in this bucket is 0.015% of the W0 traffic, average of 34.2% WML in-zone
The percents don't add to 100 perfectly as a consequence of rounding.
Generally, WML seems to be in decline across most Wikipedia Zero operators, but there are some exceptions (e.g., one operator's WML percent as defined here seems to be holding steady around 1% with this definition of WML, although I'm sort of skeptical of whether the user agent is actually WML-only or even a mobile device or is incapable of handling HTML).
We're analyzing whether WML deprecation has a disparate impact measurable enough to defer exclusive concentration on HTML, especially in light of the increasing availability of cheap mobile devices supporting HTML and the tendency for large intermediary search services and appliances to translate HTML to WML on behalf of the actual client device in the rare case of a device only supporting WML.
-Adam