condition mean min max ZT0-3 9.3 9.3 9.3 ZT4-7 8.5 8.5 8.5 ZT8-11 4.9 4.9 4.9 ZT12-15 18.45 18.45 18.45 ZT16-19 8.45 8.45 8.45 ZT20-23 7.25 7.25 7.25