Interestingly, the percentage of students securing top marks has remained stable at about 0.25 per cent, as has the mean score (about 29 points). There has been little variation year on year in the number of students attaining the diploma (78 per cent) and the mean grade (about 4.67, with the highest score being seven for each course).

However, the distribution of additional points, which students earn for the theory of knowledge and extended essay components, has shown a year-on-year increase from 0.98 in 2008 to 1.15 last year.

One of the criticisms levelled at A-levels had been the steady rise in grades for 27 consecutive years, implying that the qualification was not challenging enough for students. So do the IB statistics mean that the International Baccalaureate Organisation (IBO) has successfully maintained its academic rigour despite its phenomenal growth in recent years?

Is it able to oversee schools to ensure uniform implementation of its programmes? And is the marking of both external and internal assessments consistent, given the number of examinations has increased from 333,511 to 486,472 in the past five years?

Carolyn Adams, the organisation's chief assessment officer, says: "It is essential that students, teachers and universities have confidence in a robust qualification, which offers an internationally benchmarked standard against which to judge success."

To that end, the organisation is in the process of converting diploma programme assessment to an electronic platform that features the e-marking of exam scripts. It is also committed to making all paper and postal processes electronic across the diploma and the middle years programme.

Last year, two-thirds of the 130,000 student scripts submitted for May and November were electronically marked by examiners.

Other than reducing the cost and carbon footprint of shipping physical assessment material, one of the biggest advantages of electronic marking is the high level of standardisation that can be achieved across its 9,000 examiners. Another way is enhancing IB educators' professional growth to ensure students receive a high-quality international education.

Educators can now choose from hundreds of face-to-face and online workshops, teacher education programmes at institutions around the world, and blended courses.

To influence teacher education programmes at university level, the organisation is collaborating with 17 universities around the world, including the University of Hong Kong, to offer modules and IB educator certificates that encourage teachers to examine the principles and practices associated with IB programmes for students of all ages.

Teachers at St Paul's Co-educational College certainly made an impressive start in implementing the curriculum: the average score of its first cohort of IB students was 40.64 out of a maxium 45 points. Nearly 80 per cent achieved a score of 40 and a mean subject grade of 6.45.

Jenny Chan Chak-ling, 17, one of the five students at St Paul's who got a score of 44, says she had never been a top scorer when studying the local curriculum. She undertook the diploma programme because she wanted to study overseas and IB is more widely recognised internationally than the Hong Kong Diploma of Secondary Education exam.

The number of universities worldwide that recognise the IB now stands at 1,925.

Kim Tsoi Kin-ming, a spokesman for St Paul's, says the school started to offer the diploma in 2010 to give students more choice. "Some students have different career expectations or want to study abroad," Tsoi says. "IB has a longer history and better global recognition."

In its strategic goal of obtaining international recognition, the organisation delivered a number of critical initiatives last year.

Addressing the needs of students who might find the diploma programme challenging, the IB Career-Related Certificate was officially launched last September as the fourth IB programme, after five years as a pilot initiative. It is now offered in 44 schools worldwide.

Another new project that gives keen athletes an opportunity to gain a flexible, internationally recognised education while advancing their careers in their chosen sport will be run through the IBAEM Global Centre and the World Academy of Sport.

This initiative offers young athletes the chance to study courses over a three- to four-year period that fits into their demanding training schedules and travel commitments.

Research has continued to confirm the value of an IB education. One example is the study titled , with CPS referring to Chicago's public schools. Completed in July last year, it showed that the IB was giving higher-achieving students in local neighbourhood schools access to academically advanced coursework.

These students have a better chance of being accepted by universities, including more selective ones, and staying in university at higher rates than similar students in honours and selective-enrolment high schools.

Tsoi believes more students in Hong Kong will undertake the IB programme in the coming years, but says government-subsidised schools can only allow less than half of their students to take a non-local curriculum.

"Today's IB Diploma graduates can be confident that they possess the skills needed to excel in an increasingly international world, with students uniquely poised for success both at university and beyond," says Jeffrey Beard, director-general of the IBO.

Is this true for all students who obtain this diploma?

Nandini Ahuja, 17, from West Island School, secured 33 points, which is higher than the world average of 29.81. While she is disappointed, she still feels the IB experience has been worth it. "Having to study subjects from different subject groups has given me a range of skills which I will definitely find useful at university," she says.

Ahuja has advice for students taking the programme this autumn: "Try to finish off your CAS [creativity, action, service] requirements in the first year … so that in the second year you are able to focus on your internal assessments, mock exams and college admissions.

"Secondly, right from the beginning, clarify understanding of difficult topics with your teachers. The IB syllabus is so vast that as workload increases, the number of topics you don't understand is a significant portion of the syllabus."

Ahuja fulfils the requirements of the IB learner profile. She has learned to be "reflective" in assessing her strengths and limitations in order to support her learning and personal development.