Also in Beijing. Just in case readers don't know, the Chinese ratings are produced as a daily average, based on equipment outside the city center (i.e. near the

Also in Beijing. Just in case readers don't know, the Chinese ratings are produced as a daily average, based on equipment outside the city center (i.e. near the airport), while the US ratings are produced hourly from right downtown. So sometimes the figures are the same, but that usually only happens when coming down from the peak of a particularly bad day, when the average from the previous day's readings are pulling up the official Chinese numbers while the US figures have already fallen to reflect current conditions.