condition mean min max ZT0-3 4.019045 4.019045 4.019045 ZT4-7 2.918425 2.918425 2.918425 ZT8-11 3.023125 3.023125 3.023125 ZT12-15 4.332355 4.332355 4.332355 ZT16-19 6.1383600000000005 6.1383600000000005 6.1383600000000005 ZT20-23 4.6988199999999996 4.6988199999999996 4.6988199999999996