The United Nations Population Division considers the population aged 15 years or more as adult population. The UNESCO Institute for Statistics (UIS) collects data on adult literacy rates. These data are based on population censuses and sample surveys. According to the UNESCO Resolution of 1958, literacy is defined as the ability to both read and write, with understanding, a simple statement related to one's everyday life. In addition, the UIS is working with a growing number of countries to produce data on literacy skills through the Literacy Assessment and Monitoring Programme (LAMP).