condition mean min max ZT0-3 3.05 3.05 3.05 ZT4-7 2.1 2.1 2.1 ZT8-11 3.4000000000000004 3.4000000000000004 3.4000000000000004 ZT12-15 3.65 3.65 3.65 ZT16-19 3.5999999999999996 3.5999999999999996 3.5999999999999996 ZT20-23 7.0 7.0 7.0