condition mean min max ZT0-3 2.45 2.45 2.45 ZT4-7 2.7 2.7 2.7 ZT8-11 4.45 4.45 4.45 ZT12-15 6.65 6.65 6.65 ZT16-19 41.5 41.5 41.5 ZT20-23 9.1 9.1 9.1