That data should be related to the software products distribution.
The big explosion of web applications requires a large use of web programming languages, this leads to the grow of script languages, HTML, javascript, python, etc.
Similar reasons drive the grow of multiplatform languages/frameworks (Azure and similar).
Making 100% the whole, those new programming field apparently seems to occupy the 90%, but this is exactly the growth, more or less, of new applications. Conclusion the use of imperative strong languages, as C/C++, are the same.
Why? Because an OS, time critical programs, high efficiency computation, requires them, C/C++ and even FORTRAN sometimes.

Anyway the software/hardware development always follows the dog-tail law:
when a more powerful hardware is created there always follow a new OS or language or user interface to make it slow!
