condition mean min max ZT0-3 1.7999999999999998 1.7999999999999998 1.7999999999999998 ZT4-7 1.4 1.4 1.4 ZT8-11 2.0 2.0 2.0 ZT12-15 17.3 17.3 17.3 ZT16-19 2.55 2.55 2.55 ZT20-23 1.3 1.3 1.3