I occasionally compile some statistics on programming language popularity by running a bunch of Google searches to rank programming languages according to the number of results. I wouldn’t read too much into these stats, but they are not without value.
I’ve learned a number of programming languages since I began programming 25 years ago. Earlier in my career, my choice of which programming language to learn was largely driven by external factors such as a class or job requirement, or the expectation of job demand in the future.