Hi Leopold,

I'm not sure which survey you're asking about. From this thread, http://ros-users.122217.n3.nabble.com/ROS-Release-Timeline-td4020078.html I found two survey results. I think the first one is the one you want.

This one covers more of the OS Versions
https://drive.google.com/open?id=0BzNmzxy4pVGMNDdxNFNDblJTN1k

This covers more of the ROS Versions
https://drive.google.com/open?id=0BzNmzxy4pVGMZHd2b1BSWVlHVHM
Note that these were collected in the middle of 2013.