FEE-paying schools continue to dominate when it comes to sending students to third level, figures compiled over the past eight years reveal.
Out of more than 700 schools nationwide, just six have maintained a 100pc record in sending students on to third level in that time. Just one non-fee-paying school has maintained that perfect record since 2009.
By comparing the percentage of students who were admitted to a university after studying in a school with a perfect record, it is possible to distinguish which is the best performer overall.
Figures compiled by the Sunday Independent show Glenstal Abbey, Co Limerick, has emerged as the county's best-performing school, up two places from third on last year's list.
It pipped Presentation Brothers College in the Mardyke, Cork, to the honour by a narrow margin of just 0.08pc.
An analysis of the data shows Glenstal Abbey has sent proportionally more of its students to third level, with 292 boys sitting the Leaving Certificate at the boarding school since 2009.
Digging deeper it is possible to see that the school, which charges a €18,950 seven-day boarding fee, sends a majority of its students on to Dublin-based universities.
University College Dublin has admitted 79 Glenstal students since 2009, Trinity College admitted 68 and another 12 former pupils went on to study in Dublin City University.
Dublin leads the way as the county with the highest number of schools to maintain a perfect record in the past eight years. Three of the six schools to send all of their students on to college since 2009 are located in the capital - an unsurprising statistic given the size of its population. It is also the only county in Leinster with schools that have maintained a perfect record in the past eight years.
All of the remaining schools with 100pc records are in Munster, with counties Limerick, Cork and Tipperary represented.
Glenstal Abbey sent 80.82pc of its students to university over the past eight years. The remaining students went on to study in other colleges. Presentation Brothers College in Cork sent 80.74pc of its students to university in the same period.
Both are fee-paying, all-boys schools.
Some 75pc (662) of the 883 pupils who sat the Leaving Certificate in Presentation Brothers College went on to take up courses in University College Cork. Cork Institute of Technology is also well served by Presentation Brothers College, taking in 154 students from the school since 2009.
The school slipped one place in the Sunday Independent league table over the past 12 months to second place, while the next best performing school - Mount Anville School, in Dublin 14 - slipped one place to third.
Mount Anville remains the capital's highest-placed school and is also the country's best performing all-girls school, with 79pc of its students placed in universities between 2009 and September last year.
Former pupils have tended to stay in the capital - with more than half (52pc) of the 831 students who went through the school since 2009 moving on to study courses in University College Dublin. Trinity College took in 164 Mount Anville pupils and 111 went on to the Dublin Institute of Technology.
Colaiste Iosagain, Stillorgan, is fourth overall and the second placed Dublin school and all-girls school.
It claims the title of the country's best performing non fee-paying school.
Cistercian College in Roscrea, Co Tipperary, is the fifth best school on the list with all of its 338 former pupils securing college places in the past eight years - with 71pc placed in universities.
St Mary's College in Rathmines, Dublin 6, is the last remaining school to hold a perfect record when it comes to sending students on to third level. Some 60pc secured places in universities since 2009.
For some years now, national newspapers have published league tables of schools, ranking them by the percentage of young people who go on to higher education. These league tables have consistently shown that fee-paying schools, gaelscoileanna and all-girls secondary schools 'do better'. But what does this ranking tell us?
The publication of secondary school league tables usually engenders negative commentaries, which take aim at particular types of schools. Gaelscoileanna, fee-paying schools, or schools of a particular denomination are accused of being "private", "elitist" or "selective", and they are pitted against "public" state-funded schools.
Parents are naturally hungry for information about the secondary schools their children may attend. They can read annual school reports, some of which are very good, while some are not. For years, they have been promised a Parent and Student Charter. Education Minister Richard Bruton has finally announced draft legislation which will compel all schools to consult a lot more with parents and to publish more information. This will include details of "extra-curricular activities and school performance".
When you drive up its mile-long entrance avenue hugged by ancient trees rooted between the many streams and lakes on its 500 acres, it's easy to see why Glenstal Abbey in Murroe, Co Limerick, has the best- ranked secondary school in the State.