It would be interesting to know what the percentage is for comparable routes by other US airlines. While coach to Europe is mobbed, the business cabin is usually not (something about Europeans getting half the summer off ). It has always been easier to get a biz class award in summer than at other times of the year, although with there being so few standard summer awards available in coach these days, I suspect it's become harden (if you've got to pay "double miles," you might as well try to sit up front).