Here's what the IEEE has to say about the top 10 from the table above:
The big five—Java, C, C++, Python, and C#—remain on top, with their ranking undisturbed, but C has edged to within a whisper of knocking Java off the top spot. The big mover is R, a statistical computing language that’s handy for analyzing and visualizing big data, which comes in at sixth place. Last year it was in ninth place, and its move reflects the growing importance of big data to a number of fields.
IEEE Spectrum ranks languages using a weighted score of 12 factors including Google search rankings and trends, social media chatter, aggregator posts (Reddit and Hacker news), social programming activity (GitHub and StackOverflow), job opportunities (Career Builder and Dice) and academic citations. You can also specify your own rankings using this interactive web application (for a charge of $0.99). The application also offers rankings of trending languages (R is #10 in this list), languages in demand by employers (R is #13), and languages popular on open source hubs (R is #10). However you measure, R's ranking is impressive: as a domain-specific language for data science, the fact that it's ranking with general purpose languages like Java, C and Python demonstrates the importance of advanced data analysis in today's world.
IEEE Spectrum: The 2015 Top Ten Programming Languages