condition mean min max ZT0-3 1.2849758333333334 0.1118275 2.188035 ZT4-7 0.0976365 0.0976365 0.0976365 ZT8-11 0.2053415 0.2053415 0.2053415 ZT12-15 0.8058302500000001 0.3274355 1.2842250000000002 ZT16-19 1.1777755 1.1777755 1.1777755 ZT20-23 1.7685750000000002 1.7685750000000002 1.7685750000000002