Total number of students in pre-primary education enrolled in institutions that are not operated by a public authority but controlled and managed, whether for profit or not, by a private body (e.g., non-governmental organisation, religious body, special interest group, foundation or business enterprise), expressed as a percentage of total number of students enrolled in pre-primary education. Within ISCED 0, early childhood educational development programmes are targeted at children aged 0 to 2 years; and pre-primary education programmes are targeted at children aged 3 years until the age to start ISCED 1.