condition mean min max ZT0-3 5.047230000000001 5.047230000000001 5.047230000000001 ZT4-7 3.3345149999999997 3.3345149999999997 3.3345149999999997 ZT8-11 3.44359 3.44359 3.44359 ZT12-15 3.9907500000000002 3.9907500000000002 3.9907500000000002 ZT16-19 6.6823250000000005 6.6823250000000005 6.6823250000000005 ZT20-23 5.311395 5.311395 5.311395