Number of deaths of infants under age 1 per 1000 live births per year is referred to as

The death of infants are referred to as infant mortality ( So you can say for example "Infant mortality is a big problem for some countries) and the number of such deaths per 1000 births is called the infant mortality rate.

The infant mortality rate is very high for example in Africa and in India

Ibelieve appendix i maybe wrong