condition mean min max ZT0-3 18.62250166666667 8.724255 24.45395 ZT4-7 10.101880000000001 10.101880000000001 10.101880000000001 ZT8-11 9.015245 9.015245 9.015245 ZT12-15 14.5591 12.975850000000001 16.14235 ZT16-19 18.459699999999998 18.459699999999998 18.459699999999998 ZT20-23 29.6661 29.6661 29.6661