condition mean min max ZT0-3 5.45 5.45 5.45 ZT4-7 11.0 11.0 11.0 ZT8-11 4.2 4.2 4.2 ZT12-15 6.15 6.15 6.15 ZT16-19 31.65 31.65 31.65 ZT20-23 7.75 7.75 7.75