condition mean min max ZT0-3 8.35 8.35 8.35 ZT4-7 7.5 7.5 7.5 ZT8-11 15.600000000000001 15.600000000000001 15.600000000000001 ZT12-15 8.1 8.1 8.1 ZT16-19 3.55 3.55 3.55 ZT20-23 12.75 12.75 12.75