there's no exact amount/denomination of XVP needed for POS, the only thing I know is that its what you have in your wallet that the POS will give you in return, if you have 100xvp in your virtacoinplus wallet account, your reward will be 7% in every 24hours, I believe you should be having  0.01917808219Virtaconplus and if you are having 1000 Virtacoinplus in 24hours you should be expecting  0.19178082191Virtacoinplus. If my calculation is wrong Please stand to be corrected. The more XVP you have the more reward you get. Thanks