Well, none of those 3 languages are what I would consider "an advanced high-level language". C++ is not high-level by my definition and python and Java are certainly not advanced - well maybe Java has an advanced typesystem compared to Go, but not compared to the state of the art.
So I'm not surprised by the results, if the majority of the data came from those languages. That doesn't invalidate anything, it just changes the scope and can't be really used to backup your argument imho.