For five countries of your choice, collect annual data on macroeconomic variables (and political variables if you wish) for at least a 10 year period (which must end in 2013 or 2014, i.e. the most recent available data). Using this data, design and estimate a model to produce sovereign ratings for each country for each year.
There is documentation available on the websites of Standard & Poor’s, Moody’s, and Fitch rating agencies which will assist you in this task.