The way it used to work is that on each auction day they try to sell a certain number of bonds. Usually about the same amount for each auction day. If they did not sell or they needed more money they had special auctions as well, with better offers if needed. That was usually the case, when they offered them at too favourable conditions for the Russian government and the better offers sold the rest of the bonds easily and where usually not that much better.

So before 2/3 of the bonds should have been sold by now.