Simulating Hyperinflation for 3650 days.
If private bond holdings are going down and the government is running a big deficit then the central bank has to monetize bonds equal to the deficit plus the decrease in private bond holdings. We don't show the details of the central bank buying bonds here, just the net results.
See blog at http://howfiatdies.blogspot.com for more on hyperinflation, including a hyperinflation FAQ.