condition mean min max ZT0-3 16.211645 16.211645 16.211645 ZT4-7 21.270767499999998 21.270767499999998 21.270767499999998 ZT8-11 23.0009875 23.0009875 23.0009875 ZT12-15 20.7568095 20.7568095 20.7568095 ZT16-19 37.570453 37.570453 37.570453 ZT20-23 35.3403725 35.3403725 35.3403725