The only way that enrolment ratios can exceed 100 per cent, as Mr. Castles points out, is for enrolment to include substantial numbers of students whose age is beyond the upper end of the age range included in the denominator.
“基于购买力平价的曲线图形同基于其他兑换率的曲线相比，显示的不均现象较少，其部分原因是购买力平价仅涉及178个国家中的117个。