You can check https://www.openhub.net (ex Ohloh) that tracks open source projects. Go to the tools section and compare languages. Lisp has been in decline for a long time, based on number of contributors and projects updated. Scala is doing exceptionally well
The graph does not look very convincing. It talks about 'the number of developers', while the vertical axis is labelled in %. What is it now numbers or percent. If percent, then of what?