These point to a crucial difference: children aged 5 to 15 constitute 13 per cent of the population in OECD countries, but 30 per cent in developing countries.
这种情况显示了至关重要的差异： 5岁到15岁之间的儿童 占经合发组织国家人口的13%，但占发展中国家人口的30%。