Means and standard deviations for measures of covariates and mathematical achievement.

Units are number of correct responses except for prior academic attainment, which is sum of grades for all GCSEs where A* = 8, A = 7, B = 6 etc.本数据集的统计单位为正确作答次数，预先学业成就（prior academic attainment）除外；该指标为所有普通中等教育证书（GCSE）考试的成绩总和，其评分换算规则为A*对应8分、A对应7分、B对应6分，依此类推。