Chitika research:

One week following its release on September 18, 2013, iOS 7 users were generating more than 51% of all iOS-based Web traffic within North America. Growth has continued through the following two months, with iOS 7 usage rates surpassing the 70% mark within the continent. This makes it very likely that iOS 7 will continue to substantially outpace iOS 6 adoption, which reached 83% close to six months following its release in September 2012.

Meanwhile, Android is poking along:

Google’s latest OS dashboard reveals that 1.1 percent of active Android devices are running the new platform roughly a month after it became available. Not that its arrival is slowing down Jelly Bean’s growth, mind you. The older software now represents 54.5 percent of all Android use.

When you release a new version of your OS, the older version should drop, not gain in popularity.