I was surprised of the amount of Linux devs using C++ compared to the number of Windows devs (given the desktop marketshare). Also the fact that finance was leading sector using C++ - and by such a high margin - was unexpected to me.
Another surprising number was that Windows users use GCC almost as often as Visual Studio. GCC on Windows is kind of a PITA, and the VS toolchain is really pretty good. Maybe people go with GCC because they need proper C99/C11 support.