values that divide a sample of data into one hundred groups containing (as far as possible) equal numbers of observations
quantile - the argument of the cumulative distribution function corresponding to a specified probability: (of a sample) the value below which occur a specified proportion of the observations in the ordered set of observations
Within nine months of the end of each year Member States shall send the Commission the arithmetic mean, the median, the ninety-eighth percentile and the maximum concentration calculated from measurements of PM2,5 over any twenty-four hours within that year.
