ReadingStatus
How far into one issue the reader got.
lastPageRead is the farthest page reached, not the page currently open: going back to page 2 of an issue read to page 40 leaves both values where they were. It is what a "resume reading" action should open on — pass it to Reader.open's page.
Parameters
progress
0f to 100f, lastPageRead against the issue's page count.
lastPageRead
the farthest page reached, 1-indexed.