condition mean min max ZT0-3 4.2 4.2 4.2 ZT4-7 1.7 1.7 1.7 ZT8-11 2.4 2.4 2.4 ZT12-15 32.199999999999996 32.199999999999996 32.199999999999996 ZT16-19 9.3 9.3 9.3 ZT20-23 5.85 5.85 5.85