I guess the only answer I can give is .. I suppose it must be that old. I know for a while that some of the aerial photography in Tokyo was at least 6 years old because a building built in 2000 wasn't there, and nothing was even remotely started. (including clearing the site of other buildings) I'd not be surprised if that imagery was from 1997, though there's no way I could tell. Plus, they've gone through updating with less pretty but much more up-to-date imagery in Tokyo.