condition mean min max ZT0-3 15.600000000000001 15.600000000000001 15.600000000000001 ZT4-7 1.0 1.0 1.0 ZT8-11 28.05 28.05 28.05 ZT12-15 23.65 23.65 23.65 ZT16-19 12.75 12.75 12.75 ZT20-23 31.45 31.45 31.45