condition mean min max ZT0-3 9.140696 9.140696 9.140696 ZT4-7 10.073232999999998 10.073232999999998 10.073232999999998 ZT8-11 8.459527 8.459527 8.459527 ZT12-15 7.6016895 7.6016895 7.6016895 ZT16-19 8.415526 8.415526 8.415526 ZT20-23 8.950465 8.950465 8.950465