though ‘s Android has made some impressive leaps forward over the last two years, roughly half of its users aren’t seeing those improvements because 50.8 percent of Android devices are still running Android 2.3, known as Gingerbread.

The figure comes from ‘s developer website, whose data is based on the number of devices that have accessed ay within a given 14-day period.

As Dwight Silverman at the Houston Chronicle points out, released Android 2.3 on December 6, 2010 – two years ago this week. The new data from , updated Monday, shows that the two-year-old Gingerbread still has wider distribution than any other version of Android.

Android 4.0, known as Ice Cream Swich, appears on 27.5 percent of devices, according to ‘s data. Android 4.1 4.2, both known as lly Bean, appear on 5.9 percent 0.8 percent of devices, respectively.

Android is a much different – better – operating system than it was two years ago. Hardware acceleration, introduced in Ice Cream Swich, enables smoother navigation, while a new visual style, called “Holo,” lends a sleeker look to the interface built-in apps. has added plenty of useful features in Ice Cream Swich lly Bean as well, including a spell-checker, improved copy–paste, real-time voice dictation, an overhauled voice search app a virtual assistant called Now.

The problem is that phone makers wireless carriers tend to abon support for older Android phones before long, even high-end Android phones are lucky to get more than one major version upgrade over their lifetimes.

one makers have trouble delivering upgrades for a few reasons: Differences between ‘s Nexus hardware other Android phones require extra coding; the custom user interfaces that phone makers slap onto their hardware must be integrated with any new version of Android; the testing process required by wireless carriers requires additional time, effort resources. As a result, older phones tend to get left behind.

has tried to improve the fragmentation problem with a couple initiatives. In 2011, it announced an “Android Upgrade liance,” whose members promised to keep their phones up to date for 18 months. But that effort appeared to fall apart, this year, announced a “platform development kit” meant to assist phone makers with the upgrade process. Though it may be too early to tell if the second effort is making a difference, the fact that lly Bean adoption is still under 7 percent isn’t encouraging.

Android enthusiasts may argue that average users don’t know what they’re missing – no harm, no foul – but that’s the most tragic thing about it. A much better Android is out there, yet half of users associate the platform with an inferior experience. That can’t be good for the long-term health of ‘s mobile OS.