In this big range of figures what is hidden is that a student might not be interested/weak/slow-learner for a given subject. This takes toll from other subjects which he is good at. Its better that he gives exams when he thinks he is ready. Rather giving it at fixed time of the year.
Another opposite of the above is that a given student is good/strong/fast-learner at a given subject and still he has to stick with rest of the class and wait for the final exams.
Why not students have a choice to give the exams when they are ready. This might look like a havoc on the system. But if we consider that not all students will be giving the exams at the same time, for a given time it will be some fraction, (consider GRE, TOEFL etc.)
Consider another option students have to stick with the class/standard based system even if he is good enough to solve the problems of a given subject from higher classes/standard. Rather than having some subjects required to pass to move to the next class/standard its better if we have class/standard associated with each subject and a student has to clear the exams of that subject to be awarded certificate of learning that subject.
Consider the case of colleges asking for the students to have passed class 10+2 with some subjects. Presently students has to pass the whole 10+2. Why not simply the college asking for certificate of 10+2 for the required subjects.
Here is an infographic:
|Subjects in pipeline|