condition mean min max ZT0-3 9.55 9.55 9.55 ZT4-7 2.5 2.5 2.5 ZT8-11 17.45 17.45 17.45 ZT12-15 16.8 16.8 16.8 ZT16-19 6.35 6.35 6.35 ZT20-23 5.4 5.4 5.4