Google's Android has gained the upper hand against Apple's iOS over the last couple years, but it looks like when it comes to which mobile operating system's latest version is more adopted among its user base, iOS 7 handily defeats Android 4.4 KitKat.

According to the latest statistics from Google, 5.3 percent of Android devices now run Android 4.4 KitKat. The most popular version of Android is Android 4.1.x Jelly Bean at 34.4 percent, followed by Android 4.2.x at 18.1 percent and Android 2.3.3-2.3.7 Gingerbread at 17.8 percent. Android 4.0.3-4.0.4 Ice Cream Sandwich is the fourth more popular version of Android in use with 14.3 percent distribution and Android 4.3 Jelly Bean rounds out the top five with 8.9 percent.

The percentages are based off data collected during a 7-day period ending on April 1, 2014 and were gleaned from Google Play Store app access. Bear in mind that the percentages are intended to show the "relative number of devices running a given version of the Android platform."

Apple has had more success in proliferating its latest version of iOS, iOS 7. According to recently released data from Apple, 87 percent of users accessing the App Store during a 7-day period ending on April 6, 2014 run iOS 7. Only 11 percent still use iOS 6 and a paltry 2 percent are running an even earlier version of iOS.

Android 4.4 KitKat's slow adoption rate isn't all bad news -- the 5.3 percent figure from April reflects a jump of 2.8 percentage points from March, when only 2.5 percent of Android devices accessing Google Play ran KitKat.

There's a good reason behind Android KitKat's slower adoption rate and it has mostly to do with the Android industry. Unlike Apple, which shoots out updates to its devices directly from the horse's mouth, the Android update process is far more convoluted.

Google initially releases a new version of Android, generally termed the "vanilla" version of the firmware, and pushes it out to Google-tied devices, namely the Nexus series (the Nexus 5 smartphone, the Nexus 7 tablet, etc.). However, Android devices from manufacturers like Samsung, LG, HTC, or Sony have to wait even longer for their respective OEMs to personalize the firmware for their device. This usually involves tailoring it to each company's go-to interface (Samsung's TouchWiz, for instance) so that it stands out among competitors. This can take as long as a few months, and for Android devices tied to a carrier, the firmware then has to go through a carrier approval process where the network adds some more bloatware and fine tunes the new Android for the network. It is only after all this that the final firmware lands on Android devices.

Many manufacturers also choose to skip over Android versions, citing its lack of truly new features or the need to keep current devices one step behind upcoming releases in order to lure customers to more expensive, fresher toys. All in all, it makes it pretty hard for a new Android firmware to finally land on a device.