condition mean min max ZT0-3 1.4 1.4 1.4 ZT4-7 1.1 1.1 1.1 ZT8-11 4.2 4.2 4.2 ZT12-15 3.8 3.8 3.8 ZT16-19 2.1 2.1 2.1 ZT20-23 23.35 23.35 23.35