condition mean min max ZT0-3 7.3 7.3 7.3 ZT4-7 3.7 3.7 3.7 ZT8-11 15.3 15.3 15.3 ZT12-15 0.44999999999999996 0.44999999999999996 0.44999999999999996 ZT16-19 1.8 1.8 1.8 ZT20-23 1.2000000000000002 1.2000000000000002 1.2000000000000002