The historical trend data set was constructed using data extracted from the country risk tables that have been published twice a year since 1993 up to the current issue.
The methods involved in each of the composites of this table are given in its methodology.
To calculate the percentage changes over time the two most heavily weighted composites, economic performance and political risk, were considered.
The two values for every country in the survey were added together for the September publications for 1993, 1995, 2000 and 2005. The percentage changes over time were then calculated from the sum values obtained.
It must be noted that countries that started on a very low initial sum value obtained large percentage increases even though they experienced relatively small absolute increases. This was a limitation in the method.