Google detailed the state of Android OS versions in October and it's has shown that Jelly Bean has passed the 50% adoption rate mark. The three JB releases have all gained ground at the expense of the outdated versions. 2.3 Gingerbread still powers 26.3% of all droids, having fallen more than two percentage points since last month. It's still the second most popular single version after 4.1...
Source: http://www.gsmarena.com/android_in_october_2013_jelly_bean_crosses_the_50_mark-news-7115.php