Everything else was secondary because during that time period the dispersion of returns within and among categories of stocks narrowed tremendously, to actual all-time records.
"It is likely that the government will go into the next election having presided over an increase in secondary school class sizes during a period when the government's top priority has been education, " said the general secretary, John Dunford.
"Our aim must be that over a five to 10-year period we work towards every single secondary school within easy reach of a university being covered by such a programme, " she said.
Significant improvements have also been made in the Arab States, with the female gross enrolment ratio for lower secondary education rising from 67% to 82% over the same period.
For those enrolled in secondary education, two courses at this level of schooling are completed in each academic year which corresponds to a period of ten months.