Answer:
The country's population has a high growth rate.
Explanation:
The classification of developing countries usually includes countries with low industrial levels, a low standard of living, low life expectancy and low GDP per capita.
But some "rich" countries are also included in that list, like Qatar which has the highest GDP per capita in the world, $143,788, but the vast majority of the population is extremely poor (over 90%). The rulers of Qatar are extremely rich and their income comes exclusively from oil, they don't have any other major industries. The same applies to Saudi Arabia, United Arab Emirates, Kuwait, etc.
