What it means: the share of babies who die before their first birthday, a standard measure of a country's health and care for mothers and babies. It fell steadily for decades and has levelled off since the mid-2010s. A change of 0.1 or more on the year before counts as a change in status.

Source: ONS, child and infant mortality in England and Wales, table 1 (2023 and 2024 editions). Rates worked out from the published numbers.