What is the total amount, by type, of narcotics (a) seized and (b) destroyed by the (i) SA Police Service, (ii) the Directorate for Priority Crime Investigations and (iii) any other law enforcement agency or unit within his department in the (aa) 2012-13, (bb) 2013-14, (cc) 2014-15, (dd) 2015-16 and (ee) 2016-17 financial years?