condition mean min max ZT0-3 12.319025 12.08735 12.550699999999999 ZT4-7 38.191500000000005 38.191500000000005 38.191500000000005 ZT8-11 21.5362 21.5362 21.5362 ZT12-15 0 0 0 ZT16-19 30.024500000000003 30.024500000000003 30.024500000000003 ZT20-23 11.561045 11.561045 11.561045