[falling]

The best I know of are from single developers, not global:

http://www.quora.com/What-proportion-of-all-iPhone-owners-us...

http://www.marco.org/2011/11/30/more-ios-device-and-os-versi...

for reference, iOS 5 was released October 12, Ice Cream Sandwich on October 19.

[fpgeek]

Huh? ICS was announced on October 19th, not released. The first release didn't come until mid-November, when the GSM Galaxy Nexus went on sale.

[falling]

my bad, I checked Wikipedia and got deceived by the phrase “[…] officially launched at the Galaxy Nexus and Ice Cream Sandwich release event on 19 October 2011” but then it says only the SDK was released that day. so, one month difference instead of one week.