How can completion ratio exceed 100%?
There are many reasons why the primary completion rate
can exceed 100 percent. Most of the time, indicators
that exceed 100% use “gross” calculations. “Gross”
enrollment includes students of all ages, including
students whose age is different from the official age
group. When there is late enrollment, early enrollment,
or grade repetition, the total student enrollment can
exceed the population of the age group that officially
corresponds to the level of education – leading to
ratios greater than 100 percent.
In some countries like Hungary, Ireland, Mexico, and
Italy, completion rates have been reported over 100%.
Completion rate is calculated by dividing the number of
new entrants (gross enrollments minus repeaters) in the
last grade of that level of education, regardless of
age, by the population at the entrance age for the last
grade of the level of education and multiplying by 100.
In the case of completion rate, the numerator may
include late entrants and overage children who have
repeated one or more grades of the level of education as
well as children who entered school early, while the
denominator is the number of children at the entrance
age for the last grade of that level of education.
In summary, while it might seem counterintuitive,
completion rates exceeding 100% are possible due to the
way enrollment data are calculated and variations in
reporting methods. These rates don’t necessarily mean
that more than 100% of the population completes a
certain level of education; rather, they reflect the
complexities of educational systems and data collection.
Data Help Desk - World Bank