Eclipse Autocomplete (percent sign, in Juno)

Question

The percentage represents how likely the Eclipse Code Recommenders (archived project since July 2019) think it is that you are looking for a certain completion based on the context and maybe prior usage and other variables (there are "5 Intelligent Code Completion Engines"). It is not only the bare usage statistics. So a value might change from 13% to 95% between some lines, depending what you did in between.

See the docs for details (archived project since July 2019):

It assists developers by recommending him only those methods that are actually relevant for his task at hand. For instance, given that a developer just created a text widget makes it obvious for Code Recommenders which methods a developer wants to use next - even if the developer doesn't know it by himself.

A download of the now archived project can be found here: http://archive.eclipse.org/archived_projects/recommenders.tgz