condition mean min max ZT0-3 0.5818668333333334 0.24105300000000002 0.9503965000000001 ZT4-7 0.166832 0.166832 0.166832 ZT8-11 6.54899 6.54899 6.54899 ZT12-15 2.2343349999999997 2.118115 2.350555 ZT16-19 1.717145 1.717145 1.717145 ZT20-23 1.2853750000000002 1.2853750000000002 1.2853750000000002