Infant mortality rate (IMR) is the number of deaths of children less than one year of age per 1000 live births.
The percentage of a population of a country that can read and write. For example, the USA has a 99 percent literacy rate.
The net attendance ratio (NAR) is the percentage of the official primary school-age population that attends primary school.
Gross Enrolment Ratio (GER) is a statistical measure used in the education sector and by the UN in its Education Index to determine the number of students enrolled in school at several different grade levels (like elementary, middle school and high school), and use it to show the ratio of the number of students who live in that country to those who qualify for the particular grade level.
Life expectancy at birth is defined as the average number of years that a newborn could expect to live.