condition mean min max ZT0-3 1.7796925 1.69368 1.865705 ZT4-7 2.4297899999999997 2.4297899999999997 2.4297899999999997 ZT8-11 2.24094 2.24094 2.24094 ZT12-15 2.4100462499999997 2.3667325 2.45336 ZT16-19 1.875131 1.385922 2.36434 ZT20-23 0 0 0