Hi Ernie,
could you please provide more details about calculation of the percentage. Does 100% mean all cards are answered correct at least one time within that target interval eg 90 days?
Are all cards considered or only those which are filtered for study?
Will there be only one target interval for all decks? I use different repetition time frame for different content/decks. My suggestion is to use the already existing "maximum interval".
I like to see also the total number of cards which is at present not visible for combi-decks at least if there is a score (number of correct cards within target interval) instead of percentage.