I have no idea how to read the tables in there, so maybe they cover this, but:
Too much information is lost, in the "average selling price" statistic that graph is using, to be able to use it to definitively claim anything like "an equivalent house is selling for less than it would have before".
For example, that graph could just as well be caused by fewer high-end houses being sold, but the houses that are being sold going for the same amount they would have before.
Again, I think it's very likely bordering on totally inevitable that prices will drop, and that that graph is probably showing that. But it's not enough information by itself to make that claim.
Too much information is lost, in the "average selling price" statistic that graph is using, to be able to use it to definitively claim anything like "an equivalent house is selling for less than it would have before".
For example, that graph could just as well be caused by fewer high-end houses being sold, but the houses that are being sold going for the same amount they would have before.
Again, I think it's very likely bordering on totally inevitable that prices will drop, and that that graph is probably showing that. But it's not enough information by itself to make that claim.