(a) What number of qualified engineers have left Eskom in each of the past 10 years in terms of the highest qualification level, date of employment, gender and race, (b) what number of consultants or external advisers are currently contracted by Eskom to provide technical services related to engineering and (c) in each instance, (i) through which company are they contracted, (ii) what amount are they being paid, (iii) are the specified persons former employees of Eskom and (iv) what is the highest qualification level, gender and race of each person?