Overview of data collection and response rates per country.

1response rate is the percentage of children that completed the child questionnaire of the children with parental consent. 2response rate is the percentage of children that completed to child questionnaire of the total number of eligible children. 3response rate is the percentage of children with completed parent questionnaire of the children with parental consent. 4response rate is the percentage of children with completed parent questionnaire of the total number of eligible children.