I don't think the max case number for Asia is 18000. It could be 12000 or less for dv2013. So the question is why the case number only up to 12000 and we have about 17000 selectee in 2013. Even without holes, it is still not enough for the 17000 selectee to fit not the max case number. The only explanation I can think of is dependents or derivatives. Only with this explanation make complete sense to me because it only process 1000 or less per month and based on Asia allotment, it like there are no holes and everyone have submitted their application in times. This is near impossible to me. So, my theory is this. Each month DOS might allocate said 700-800 visa and it only take the case number about 1000 range. And if there is 40% are holes and no application, it only takes about 600 and the others are derivatives allotment.
So for dv2014 is different, it might have less dependents applicants being selected,that's why the case number is higher and it will run faster compare to 2013. All this is just my thought.