condition mean min max ZT0-3 20.97155 20.97155 20.97155 ZT4-7 22.71665 22.71665 22.71665 ZT8-11 15.00565 15.00565 15.00565 ZT12-15 17.651175 17.651175 17.651175 ZT16-19 66.0676 66.0676 66.0676 ZT20-23 12.574324999999998 12.574324999999998 12.574324999999998