condition mean min max ZT0-3 11.9556 11.9556 11.9556 ZT4-7 12.015585999999999 12.015585999999999 12.015585999999999 ZT8-11 11.5045425 11.5045425 11.5045425 ZT12-15 14.054408 14.054408 14.054408 ZT16-19 13.64378 13.64378 13.64378 ZT20-23 17.0620205 17.0620205 17.0620205