The data of the restaurant challenge is hosted at Kaggle:
(you might need to register an account)
And the KNIME workflow can be downloaded from the Examples Server
It could be that for your specific problem you would have to use some time series models. And you would have to think about you model setup. Do you have additional information about the countries or do you just have 2 numbers per county (GDP and unemployment). If so that would imply that you could create something like a general rule and that might be tricky but you could try. You might have to deal with outliers if a country had a very unusual year.
If you have the data you might share it so people could have a look.