The last one:
The previous one:
That is the 9. from the last one (last is 0).
Bar 8 would be the 8th previous candle (9 if you count the current candle), which would span the 5-minute time beginning 8*5 minutes back + how ever many minutes you are into the current candle. So if the current candle just opened then bar 8 would open 40 minutes ago and close 35 minutes ago.
BTW, I just sent you a PM message about your EA. Don't know how often you check those so I though I'd let you know.
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