condition mean min max ZT0-3 2.7793625 2.495235 3.06349 ZT4-7 2.057895 2.057895 2.057895 ZT8-11 3.019095 3.019095 3.019095 ZT12-15 0 0 0 ZT16-19 3.47928 3.47928 3.47928 ZT20-23 3.6973200000000004 3.6973200000000004 3.6973200000000004