In other countries, mainly in East Asia and Eastern Europe, fertility rates have fallen well below replacement-level fertility of roughly 2 children per woman. However, the population is not yet declining in most of those countries, owing to population momentum, except in countries such as Japan that are most advanced in the demographic transition (Fischer, 2014). During the period from 2005 to 2010, the 75 countries with below-replacement fertility made up 48 per cent of the world's population (United Nations, 2013c).