出生率
Birth rates vary even within the same geographic areas. In Europe, as of July 2011, Ireland's birth rate is 16.5 per cent, which is 3.5 per cent higher than the next-ranked country, the UK. France has a birth rate of 12.8 per cent while Sweden is at 12.3 per cent. In July 2011, the UK's Office for National Statistics (ONS) announced a 2.4% increase in live births in the UK in 2010 alone. This is the highest birth rate in the UK in 40 years. By contrast, the birth rate in Germany is only 8.3 per 1,000, which is so low that both the UK and France, which have significantly smaller populations, produced more births in 2010. Birth rates also vary within the same geographic area, based on different demographic groups. For example, in April 2011, the U.S. CDC announced that the birth rate for women over the age of 40 in the U.S. rose between 2007 and 2009, while it fell among every other age group during the same time span. In August 2011, Taiwan's government announced that its birth rate declined in the previous year, despite the fact that it implemented a host of approaches to encourage its citizens to have babies.