Birth rate
According to the CIA's "The World Factbook", the country with the highest birth rate is Niger at 6.49 children born per woman and the country with the lowest birth rate is Taiwan, at 1.13 children born per woman.
Demographics of France
The immigration rate is currently lower than in other European countries such as United Kingdom and Spain; however, some say it is unlikely that the policies in themselves account for such a change. Again, as in the 1920s and 1930s, France stands in contrast with the rest of Europe. Back in the 1920s and 1930s, when other European countries had a high fertility rate, France had a low fertility rate and opened its doors to immigration to avoid a population decline. Today, it is the rest of Europe that has very low fertility rates, and countries like Germany or Spain avoid population decline only through immigration. In France, however, the fertility rate is still fairly high for European standards. It is, in fact, the highest in Europe after Ireland (the EU) and Albania (perhaps higher than Ireland's) and so most population growth is due to natural increase, unlike in the other European countries.