(a) What number of cases of (i) fruitless, (ii) wasteful and (iii) irregular expenditure in his department were identified by the Auditor-General in the (aa) 2014-15, (bb) 2015-16 and (cc) 2016-17 financial years, (b) what was the amount in each case and (c) how much of the specified amount has been recovered in each case?