condition mean min max ZT0-3 2.5719250000000002 2.5719250000000002 2.5719250000000002 ZT4-7 1.6566200000000002 1.6566200000000002 1.6566200000000002 ZT8-11 2.5125349999999997 2.5125349999999997 2.5125349999999997 ZT12-15 3.01637 3.01637 3.01637 ZT16-19 4.263165 4.263165 4.263165 ZT20-23 3.346995 3.346995 3.346995