condition mean min max ZT0-3 2.15 2.15 2.15 ZT4-7 1.7 1.7 1.7 ZT8-11 3.5999999999999996 3.5999999999999996 3.5999999999999996 ZT12-15 3.1 3.1 3.1 ZT16-19 3.6 3.6 3.6 ZT20-23 9.9 9.9 9.9