condition mean min max ZT0-3 9.22632 7.65527 11.4373 ZT4-7 8.640695000000001 8.640695000000001 8.640695000000001 ZT8-11 7.504545 7.504545 7.504545 ZT12-15 19.855925 18.388550000000002 21.3233 ZT16-19 10.39233 10.39233 10.39233 ZT20-23 7.009065 7.009065 7.009065