[toyg]

IMHO there is a substantial distinction to be made, when running statistics, between languages that are effectively corporation-sponsored (Java, C#, JS, etc) and opensource "community" languages (Perl, Python, C, etc).

The former tend to peak early, powered by marketing departments, and then slowly tail off; the latter tend to do the opposite, because word-of-mouth is slow; community-powered peaks are often determined more by the appearance of a successful product based on it (Rails, Elixir, etc) than time from creation.

[pron]

Except C and Perl peaked relatively early, too, and so did PHP. Yes, Ruby was late but its super-popularity was short-lived. Python is really the only example I can think of, and even Python had a healthy usage relatively early.