What (a) is the comparative increase in rand amount and percentage, year on year, in equitable share provision for (i) Dr Beyers Naudé, (ii) Makana, (iii) Ndlambe, (iv) Sundays River Valley and (v) Blue Crane Route Local Municipalities from 2015-16 to 2019-20 financial years and (b) are the determining factors on which the calculation in increase was made?