I'm assuming the question is actually thus:
"The top 20 undeveloped nations with the largest (absolute) population growth will account for what percentage of the total world population increase by 2025?"
One of the big problems is that "undeveloped" is very vague and subjective. I'm going to answer as if "undeveloped" means any country OTHER than the fully developed ones; which means all counties other than the following:
By excluding those countries, you should then look at tables containing both the current population of countries, and the population growth rate of countries.
As a benchmark, total population as of now (2011) is just reaching 7 Billion. Estimated world population in 2025 is just over 8 Billion. Thus, we expect 1 Billion increase in the next 15 years (about 1.17% yearly rate).
In absolute terms, here are the top 25 countries, ranked by total population increase (numbers in parenthesis are population growth from 2010 to 2025, in millions):
If we exclude the United States from the above list (as a "developed" country), the top 20 list then accounts for 825 million, or about 80% of the total expected growth.
It will grow more slowly than in developin countries.
It will grow more slowly than in developin countries.
Transitional countries tend to have age structures that share similarities with both least developed and most developed nations. They may have a large youth population like least developed nations due to high birth rates, while also experiencing an aging population characteristic of most developed nations as life expectancy increases. This mix of demographic features highlights the complex and dynamic nature of transitional countries as they navigate economic and social development.
The average population growth rate for developed nations is typically low, often ranging from 0% to 1% per year. Many developed countries experience stagnation or even decline in population due to low birth rates and aging populations. Some nations may see slight increases due to immigration, but overall growth rates remain modest compared to developing nations.
The population growth rate of developing countries tends to be higher than that of developed countries. Factors such as high fertility rates, improved healthcare leading to lower mortality rates, and limited access to family planning services contribute to this faster growth in developing nations. This can put pressure on resources and infrastructure in these countries.
Because the growth of Suburbs has been a population trend in developed nations since about 1950.
Many countries are destroying the ozone. The developed nations are on top.
The United Nations 2009 estimate for the population of Angola was 18,498,000.
Belize is a developed country. Countries are described as developed countries when they have a developed economy, and an advanced technological infrastructure when compared to other developing nations.
All countries in Europe are considered developed. The most developed of these nations, however, include Norway, the Netherlands, Ireland, Germany, and Sweden.
A figure of 107,000 may be Aruba's population for 2009. That's the estimate by the United Nations Population Division. Aruba ranks 187th in population in the U.N. list of countries by population for 2009. Over one-third of the population lives in the capital of Oranjestad.
The developing nations will have to wait for the financial flows from the developed countries.