condition mean min max ZT0-3 2.7 2.7 2.7 ZT4-7 0.5 0.5 0.5 ZT8-11 9.600000000000001 9.600000000000001 9.600000000000001 ZT12-15 14.45 14.45 14.45 ZT16-19 1.75 1.75 1.75 ZT20-23 4.25 4.25 4.25