condition mean min max ZT0-3 0.15550933333333333 0.0 0.3520235 ZT4-7 0.2240835 0.2240835 0.2240835 ZT8-11 2.120295 2.120295 2.120295 ZT12-15 1.5925285 0.961932 2.223125 ZT16-19 1.2333699999999999 1.2333699999999999 1.2333699999999999 ZT20-23 0.6199 0.6199 0.6199