condition mean min max ZT0-3 2.65 2.65 2.65 ZT4-7 2.2 2.2 2.2 ZT8-11 3.4 3.4 3.4 ZT12-15 4.6 4.6 4.6 ZT16-19 2.95 2.95 2.95 ZT20-23 2.4000000000000004 2.4000000000000004 2.4000000000000004