condition mean min max ZT0-3 3.285045 3.285045 3.285045 ZT4-7 2.66243 2.66243 2.66243 ZT8-11 2.56351 2.56351 2.56351 ZT12-15 3.565485 3.565485 3.565485 ZT16-19 4.297675 4.297675 4.297675 ZT20-23 3.247785 3.247785 3.247785