condition mean min max ZT0-3 5.9870475 5.316065 6.65803 ZT4-7 3.480045 3.480045 3.480045 ZT8-11 2.3909399999999996 2.3909399999999996 2.3909399999999996 ZT12-15 0 0 0 ZT16-19 9.450325 9.450325 9.450325 ZT20-23 9.560755 9.560755 9.560755