condition mean min max ZT0-3 7.462384999999999 7.09655 7.82822 ZT4-7 10.568085 10.568085 10.568085 ZT8-11 8.077885 8.077885 8.077885 ZT12-15 0 0 0 ZT16-19 9.2187 9.2187 9.2187 ZT20-23 8.324325 8.324325 8.324325