Revealed: GCSE league table for Northern Ireland 2018 - where did your school rank?
Six Northern Ireland grammar schools scored 100% pass rates at GCSE in terms of five or more A*-C grades, including the core subjects.
Today the Belfast Telegraph publishes the second part of its annual guide on the performance of every post-primary school here.
The top six at GCSE level are Aquinas Diocesan Grammar School in south Belfast; Assumption Grammar School in Ballynahinch; Down High School in Downpatrick; Our Lady and St Patrick's College in east Belfast; St Louis Grammar School in Ballymena, and St Mary's Grammar School in Magherafelt.
The number of schools scoring 100% has dipped from the previous year, when nine schools saw all of their students achieve five or more GCSEs at grades A* to C, including core subjects English and maths. Grammar schools dominated the top of the league tables for GCSE results achieved in 2017, taking the top 54 places.
The Belfast Telegraph's league tables include data on every secondary school in Northern Ireland.
The top non-grammar school at GCSE in 2016/17 was St Patrick's High School, Keady (91.3%), followed by St Colm's High School in Draperstown (87.7%), and St Patrick's College, Maghera (85.9%) - just ahead of the top performing controlled non-grammar, Castlederg High School (83.3%).Overall across Northern Ireland in 2016/17, some 70.3% of year 12 pupils achieved five or more GCSEs at grades A*-C (or equivalent) including English and maths.
This was up 2.4 percentage points from 2015/16.
Peter Dobbin, principal of Assumption Grammar, described its joint topping of the latest league tables as a surprise 85th birthday present for the Co Down school.
"I am delighted with the phenomenal achievement of our Assumption girls at both GCSE level and A2 level," he said.
"The girls and the staff of Assumption have worked so hard and fully deserve this public recognition of our academic success.
"However, it is the school's 'Fully Alive' ethos which underpins every aspect of why Assumption Grammar is such a unique educational establishment and has been since we were first established by the Missionary Sisters of the Assumption 85 years ago this year.
"This is a surprise birthday present which will bring a smile to all our Assumption girls, past and present."
Down High principal Maud Perry said the school was very proud of its results and she paid tribute to the hard work of pupils.
"We celebrate the many talents and achievements of all our pupils at Down High and we're very proud of the 100% pass rate at GCSE in both mathematics and English," she said.
"Our motto 'nothing is achieved without effort' reflects our belief that there is no limit to what can be accomplished through hard work.
"This hard work of staff and pupils, alongside the support of our parents, produced these fantastic results in the 2017 summer exam season."
Today's tables also represent a triumph for south Belfast grammar school Wellington College, which scored 94.7%, significantly above the Northern Ireland average, as it works to be removed from formal intervention.
Principal David Castles said: "We are very proud of the excellent GCSE outcomes our students have attained. This significant improvement is part of our drive at Wellington College to raise standards, engage students and build pathways to success.
"Excellence in exams is a result of students, staff and parents working together, and these GCSE results give a great foundation for success at A-level and beyond."
How we did sums for the latest league tables
The Belfast Telegraph is the only source of comprehensive league tables showing the results of every post-primary school in Northern Ireland.
We obtained the data from the Department of Education for A-level and GCSE examinations sat in the 2016/17 academic year and compiled the figures into easy-to-read league tables, ordered from top to bottom. In the GCSE league tables, the Belfast Telegraph has used the percentage of pupils in the final year of a level 3 course who achieved five or more GCSEs - including English and Maths -between an A* to C grade in each school as the standard measure.
The Department of Education does not produce A-level or GCSE league tables and said it does not endorse them.