Is there a reliable memory-retention guidance chart? As discussed here reliability of some charts are dubious. I would like to use such a chart for studying purposes and am looking for something peer-reviewed or as factual as possible. Does it exist?
I think you can use this graphic:



It is taken from an article from WIRED, Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm. It talks about Piotr Wozniak and his spaced repetition software SuperMemo.