condition mean min max ZT0-3 6.579931666666666 2.4912650000000003 9.049285 ZT4-7 6.334255000000001 6.334255000000001 6.334255000000001 ZT8-11 17.82465 17.82465 17.82465 ZT12-15 27.724449999999997 21.128999999999998 34.3199 ZT16-19 35.73295 35.73295 35.73295 ZT20-23 23.98605 23.98605 23.98605