condition mean min max ZT0-3 6.44786 3.818895 7.82817 ZT4-7 3.01642 3.01642 3.01642 ZT8-11 2.30974 2.30974 2.30974 ZT12-15 4.7807525 3.783625 5.77788 ZT16-19 6.497954999999999 6.497954999999999 6.497954999999999 ZT20-23 9.175830000000001 9.175830000000001 9.175830000000001