The latest tracking stats for Windows phones have been released by advertising network AdDuplex, which monitors usage across its network to create a detailed monthly breakdown of Microsoft's mobile ecosystem. Each month, the reports capture a snapshot of worldwide usage across one 24-hour period - in this case, July 20, 2016.

Windows 10 Mobile grew by 1% over last month (compared with a 0.5% increase in June), but it still accounts for just 11.9% of active Windows handsets. Notably, Windows Phone 8.1's piece of the pie also increased very slightly, from 78.8% last month up to 79.1%.

This doesn't necessarily mean that there's been a surge in Windows Phone 8.1 and Windows 10 Mobile device sales since June. Windows Phone 7.x usage dropped by 1.1%, and Windows Phone 8 by 0.2%, during the same period - it's possible that many users of these much older handsets have simply left the platform entirely, pushing up the platform share of the newer OS versions. Given what we know about declining Windows phone sales in recent months, along with indications that many Windows handsets users are migrating to rival platforms, it would be wildly optimistic to presume that owners of these older devices are upgrading to new Windows phones.

This data also reaffirms what we knew yesterday, when Microsoft revealed that it is dropping Skype support for Windows Phone 8 and 8.1 handsets. That move will affect a combined total of more than 85% of current Windows phone users, as the company says it will instead focus its smartphone development efforts for Skype on iOS, Android and Windows 10 Mobile.

AdDuplex also provided an indicative breakdown of Windows phone OS usage across eight major markets. In many countries, Windows 10 Mobile usage is around the same as the global average, but it's reached exceptionally high usage in Germany, where more than 25% of Windows handsets are apparently running the newest OS version.

The list of top 10 devices around the world running Windows 10 Mobile is unchanged compared with last month, with the top two spots still occupied by the Lumia 535 and Lumia 640 - both of which shipped with Windows Phone 8.1 onboard. All four devices built for Windows 10 Mobile are in the top 10; Lumias 550, 650, 950 and 950 XL account for a combined total of 27.8% of devices running the new OS.

AdDuplex also provided a breakdown of the most popular handsets running Windows 10 Mobile among enthusiasts. The lower-mid-range Lumia 640 and Lumia 640 XL occupy the top two spots there, but they're followed closely by the newer Lumia 950 and 950 XL flagships.

Across all Windows phone OS versions, the Lumia 535 appears to have firmly established its lead as the most popular handset in use, with usage of the older Lumia 520 now in decline. None of Microsoft's newest Windows 10 Mobile devices have made it into this top 10 list yet.

This is the chart that continues to spell bad news for Microsoft month after month. In 2014, Microsoft signed up dozens of new hardware partners to build Windows mobile devices. Last year, it scaled back its own phone business in the hope that doing so would allow its partners to sell more of their own handsets.

And yet, Lumia devices continue to account for 97% of all Windows phones in use. Three of the manufacturers in the top five stopped making Windows handsets long ago.

This is no great surprise; even as Microsoft's own phone sales have plummeted by over 70%, all of its partners only managed to sell a combined total of around 100,000 Windows phones during the entire first quarter of this year. Even one of the most intriguing and thoughtfully designed Windows 10 Mobile handsets has struggled to gain interest from more than a few hundred people worldwide in the last few weeks.

Interestingly, AdDuplex also provided a breakdown of Windows phone usage in Japan, a market that has seen a wide range of Windows 10 Mobile devices being unveiled by domestic brands. The MCJ (Mouse Computer) Madosma Q501, an upper-mid-range handset, tops the list (you might also recognize that device as the Coship Moly PcPhone W6).

The Katana 01, a lower-end handset, takes the number 2 spot, with the NuAns NEO and VAIO Phone Biz - both Japan-only devices - in 4th and 5th places, respectively. The Lumia 535 is the only Microsoft device in the Japanese top 5.

These are certainly interesting stats - but it's worth bearing in mind that Windows phones aren't exactly popular in Japan. According to the latest data from Kantar Worldpanel ComTech, Windows phones account for 0.1% of total smartphone sales there, down from a peak of 1.4% in May 2014 - although that's still an improvement on the statistically insignificant sales market share of 0.0% in December 2015.

You can check out the full summary of this month's AdDuplex report here, and the detailed monthly report will be published tomorrow on the AdDuplex blog.