Scala's the only one of these three languages with any adoption right now. Groovy is virtually only used in its original dynamic mode from 2003 for things like scripting and Gradle build files, and very few people use the @CompileStatic mode introduced in 2012. Kotlin 1.0 has just been released, was subjected to stringent QA, and I expect JetBrains to use it more and more in its own products like IntelliJ, so it's a good bet it will become more popular with developers. So I'd say use Scala and Kotlin if you need static typing. Clojure, though it doesn't have static typing, has other features like syntactic macros for terseness, default immutability, and concurrency that would recommend it in many situations.

Here in Germany you almost don't hear about Groovy anymore in any JUG event.

If it wasn't for Gradle and Android adopting Gradle, I bet we would hear even less about it.