As is agreed there have been 3 previous versions of the matrix, the first two humans did not accept because there was no choice however the third version did involve choice and therefore the humans accepted it, well 99.9% anyway.
But let me say this when the anomaly goes to the source and the matrix reloads, does the matrix change, or is it merely just reset and started again?
When the matrix is reloaded there is no change, so why is this a new version? When you play a computer game, turn it off and reload the game it is not a new version but just a new time of playing the same version, this is what as happened to the matrix, Version 1 and 2 failed but version 3 was a success, the anomaly you can say is playing and when goes to the source the game is complete, the matrix is then reloaded with a new anomaly (or new player). To play the matrix again (exactly as the pervious anomaly did) a new anomaly is created, so you can say there have been 5 pervious version of the anomaly or 5 pervious players of the matrix version 3.
So to round it up, for there to have been 5 or more pervious versions of the matrix, the matrix must change every time it is reloaded(which no mention of this is in the films), and as I said there have been 3 previous versions of the matrix, and 5 pervious versions of the anomaly (or 5 pervious players of the matrix version 3)
Regards godfather