condition mean min max ZT0-3 2.5999999999999996 2.5999999999999996 2.5999999999999996 ZT4-7 5.4 5.4 5.4 ZT8-11 12.1 12.1 12.1 ZT12-15 2.6 2.6 2.6 ZT16-19 2.75 2.75 2.75 ZT20-23 2.0 2.0 2.0