min vs max and either mean or average - that's about all I remember with that. I like using a data's own min/max and then adding some arbitrary breathing room above and below if there's more data coming in. Then, anything outside of that I decide whether or not I should lower the floor or raise the roof a bit, or toss it out as an outlier. I don't like tossing out outliers, so I put them aside 'cause they might matter later for something else. smile emoticon == I got things I could complain about but it's not my way. Fix what breaks when I can and what I can't, work around it. == Yeah. Sometimes I choose all of the above. Sometimes I pick a, c, f when they say "pick only one". Sometimes I pick none of the above. Sometimes I just let the noisiest person in the room do the picking and don't care what's picked, which would mean "any of the above". Free for me is any of it, some of it, all of it, none of it, whatever I feel like / seems right to me. ==