condition mean min max ZT0-3 1.0949206666666667 0.413763 1.647499 ZT4-7 0.388799 0.388799 0.388799 ZT8-11 1.20452 1.20452 1.20452 ZT12-15 5.0509975 4.00206 6.099935 ZT16-19 2.2887500000000003 2.2887500000000003 2.2887500000000003 ZT20-23 2.9965599999999997 2.9965599999999997 2.9965599999999997