A deck’s ⋯ › Export for Anki… makes an .apkg of it; the shelf’s ⋯ › Export library for Anki… makes one of every deck, archived ones too. Open it in Anki (File › Import on a computer), and it carries:
- the cards as you edited them, with their pictures and sounds;
- when each is due, and which are suspended, flagged or marked;
- the review history.
In Anki, the cards use two note types named RectoVerso and RectoVerso Cloze. Their last field, also named RectoVerso, keeps what Anki has no place for: each answer’s effort, and the card’s memory. Leave it as it is: bring the file back to RectoVerso later, and the deck comes back with its history, including what you studied in Anki.