condition mean min max ZT0-3 1.9801725000000001 1.9431600000000002 2.017185 ZT4-7 1.40776 1.40776 1.40776 ZT8-11 1.8773149999999998 1.8773149999999998 1.8773149999999998 ZT12-15 0 0 0 ZT16-19 1.336545 1.336545 1.336545 ZT20-23 1.94663 1.94663 1.94663