condition mean min max ZT0-3 11.972461666666666 5.917135 17.313049999999997 ZT4-7 5.634095 5.634095 5.634095 ZT8-11 9.630790000000001 9.630790000000001 9.630790000000001 ZT12-15 18.9392 16.299 21.5794 ZT16-19 23.2123 23.2123 23.2123 ZT20-23 17.5803 17.5803 17.5803