I have around a million sets of 8 datapoints. I would like to rank these sets of 8 data points. I am trying to identify sets where there is a single extreme value and the other 7 datapoints are of similar value. For example, $\{0.2, 0.19, 0.27, 0.17, 0.3, 0.21, 0.22, 0.98\}$ would be considered a high-ranking set. Values can be positive or negative.

It is important that the single extreme value is larger than the other values. i.e. an extreme negative value where all other points are of similar positive value is not considered a high-ranking set.

I am currently using the variance of each set but I was hoping somebody could lend some insight into perhaps a more appropriate technique.

Thanks