Google (GOOGL) this week released its monthly update about how many users worldwide are running the different versions of its mobile operating system. The company revealed that just 7.5% of Android devices are running on its latest version, Marshmallow.

Meanwhile, more than 35% of users are running Android 5.0 Lollipop, which premiered in 2014. Another 32.5% are running the nearly three-year-old Android 4.4. KitKat.

The information provided by Google is critical to app developers, who need to know which operating systems their apps must support. They also want to know which systems they can dump as users move to newer versions of Google’s operating system.

To others, however, the findings shed light on how well Google and its hardware partners are doing at getting users to update to the latest operating systems. For users, getting to the latest operating systems should be appealing because they come with improved security and new features.

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Google’s seeming inability to get users to its latest operating system has long been a point of contention among its fans and critics. The company’s supporters say that so-called “Android fragmentation” is overblown, and the spread illustrates a diverse universe of devices running different devices. They’ve also called on Google’s hardware partners to do a better job of updating their devices to new operating systems—something many companies have been loath to do.

Detractors, however, point to Apple (AAPL) and its ability to get users to the latest operating systems. Indeed, Apple’s iOS 9 was able to secure 11% market share when it was released in the fall, and as of mid-April, was running on 84% of Apple’s devices.

That said, Apple and Google are living in much different environments. Apple is the only company selling iOS devices, and pushes out its latest operating system to users without needing to worry about third-parties doing the job. Google, however, needs to get vendors to sign on to its new operating system and then hope that wireless carriers push those updates over their networks to phones. In many cases, that doesn’t happen.

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Still, it’s an issue. And likely not one that will be addressed anytime soon: There are still millions of devices running on Android’s Gingerbread, an operating system that was first released in 2010.

Google declined to comment on Android’s distribution.

Update 2:06 p.m. to include Google’s response for comment on the distribution.