That changes each round depending on how much DHEDGE is in that round. This round had 7278.40781561 DHEDGE in it, and you need to have a minimum of 0.51% of that amount to receive an upvote. So for this round you would have needed 37.11987986 DHEDGE.

We are about to do a token split in a few days, and a new token issued and airdropped that will take over all round based voting, splitting that functionality away from DHEDGE. After that it will be issued as payment for delegations to @dhedge. If you are looking to increase your share, a little delegation will be the best way to do that within the next week.