What does infant mortality rate refer to?
1
The ratio of the number of children who die before their fifth birthday out of every 1000 live births.
2
The ratio of the number of children who die before their first birthday out of every 1000 live births.
3
The ratio of the number of children who die before their fifth birthday out of every 100 live births.
4
The ratio of the number of children who die before their first birthday out of every 100 live births.