The following data are real data sets of the "World Bank" and the "Sustainable Development Solutions Network" of the United Nations for the year 2019.
The following key indicators are provided to help you estimate the GDP per capita for each country.
| Key indicator | Explanation | Lowest value | Highest value |
| Broadband subscriptions | Broadband subscriptions are fixed subscriptions (per 100 inhabitants) for internet access via cable modem, DSL, or satellite broadband. It excludes subscriptions that have internet access via mobile networks (e.g., smartphone contracts). The broadband subscriptions (per 100 inhabitants) are normalised to 100. 100 represents the country with the most broadband subscriptions (per 100 inhabitants) and 0 the country with the fewest ones. | 0 | 100 |
| CO2 emissions | Carbon dioxide emissions come from the combustion of fossil fuels. Here, the CO2 emissions are measured in tonnes per capita and normalised to 100. 100 stands for the country with the highest CO2 emissions per capita and 0 for the country with the lowest ones. | 0 | 100 |
| Happiness index | The happiness index compares the life satisfaction of people in different countries of the world. 100 stands for the country with the highest life satisfaction and 0 for the country with the lowest one. | 0 | 100 |
| Life expectancy | Life expectancy indicates how many years a newborn will live on average. Life expectancy is standardised to 100. The highest life expectancy is, therefore, 100 and the lowest one 0. | 0 | 100 |
On the next page, you can see as examples the key indicators and the GDP per capita for Germany and Bolivia.