There is also the strange category of " Number of aircraft arrivals operated outside the runway alternation pattern (excluding TEAM arrivals or emergencies)" which would be clearer if there was a bit of commentary explaining what was going on. I guess situations where they shift the whole landing runway from the designated one to the other because it is more suitable for cross-winds would be appropriate to go in that box.
I would agree with that theory were it not for the fact that on the 2 windy days right at the end of November, when landings were swapped back to 27L in the afternoon/early evening, those values are shown as zero. Which is fair enough, I suppose, as you could argue that landings were still conforming to an ad hoc, weather-related change in alternation.
Having said that, the only day where the stats do show a sizeable "operated outside the runway alternation pattern" total (35, in fact) was a couple of weeks later (Sun 18th December) when the exactly same thing happened - strong SSW winds resulting in 27L being used for a couple of spells in the late afternoon.
Go figure.
And then there are out-of-alternation landings that aren't counted at all, like last Friday evening's BMI from Vienna, which landed between a couple of 27R departures. The "post-0700 TEAM" and "out of alternation" totals for that day are both zero, so was it therefore classed as an emergency landing ?
The sad part is that, now Phase I of the trial is over, some serious debate and decision-making on Future Heathrow needs to happen (cf On the Beach's post) - but that process doesn't stand a chance if the various parties involved can't even agree over basic statistics on what happened during the trial.