The part about inflation isn't accurate. The inflation funding doesn't come from the return proposal (and as such isn't affected by how much funding goes to other proposals). It gets added directly into the DHF account hourly via a virtual operation that you can see on hiveblocks (or another explorer that shows virtual ops):
Since you are graphing the wrong thing, your graphs don't show the right rate of funding from inflation and you might want to redo them.
RE: One Year Of Decentralized Hive Fund | Funding the Hive development in a decentralized manner