Show Jacoco coverage data

using IDEA Ultimate 13.1.6

Given the project:

https://github.com/DeziderMesko/RobotframeworkCodeCoverage

and running:

$ mvn clean install

this generates:

target/javoco.exec

target/site/jacoco/

If I open the html report in browser, it looks fine:

But if open the jacoco.exec in intellij it looks wrong:

What is the right way to show jacoco coverage data in intellij?