condition mean min max ZT0-3 2.0447949999999997 2.0447949999999997 2.0447949999999997 ZT4-7 2.29583 2.29583 2.29583 ZT8-11 2.22788 2.22788 2.22788 ZT12-15 1.507705 1.507705 1.507705 ZT16-19 2.26984 2.26984 2.26984 ZT20-23 1.829475 1.829475 1.829475