With reference to each community education and training college, (a) what number of subjects did learners enrol for in respect of the (i) Senior Certificate and (ii) National Senior Certificate examination cycles in each of the past three academic years and (b) of the specified subjects, (i) what number of subjects were eventually written and (ii) what number of students achieved marks (aa) equal to 40% and above and (bb) between 30% and 40% in each case?