condition mean min max ZT0-3 3.101551666666667 1.77699 3.7658750000000003 ZT4-7 3.0211135000000002 3.0211135000000002 3.0211135000000002 ZT8-11 3.042647 3.042647 3.042647 ZT12-15 11.5696445 5.121389 18.0179 ZT16-19 9.767415 9.767415 9.767415 ZT20-23 15.589 15.589 15.589