condition mean min max ZT0-3 6.25 6.25 6.25 ZT4-7 2.5 2.5 2.5 ZT8-11 14.549999999999999 14.549999999999999 14.549999999999999 ZT12-15 1.6 1.6 1.6 ZT16-19 2.75 2.75 2.75 ZT20-23 8.1 8.1 8.1