condition mean min max ZT0-3 30.950000000000003 30.950000000000003 30.950000000000003 ZT4-7 29.6 29.6 29.6 ZT8-11 29.15 29.15 29.15 ZT12-15 27.0 27.0 27.0 ZT16-19 37.05 37.05 37.05 ZT20-23 7.9 7.9 7.9