condition mean min max ZT0-3 7.15 7.15 7.15 ZT4-7 3.4 3.4 3.4 ZT8-11 2.7 2.7 2.7 ZT12-15 12.55 12.55 12.55 ZT16-19 5.1 5.1 5.1 ZT20-23 5.4 5.4 5.4