condition mean min max ZT0-3 5.25 5.25 5.25 ZT4-7 7.3 7.3 7.3 ZT8-11 21.65 21.65 21.65 ZT12-15 12.5 12.5 12.5 ZT16-19 19.4 19.4 19.4 ZT20-23 9.7 9.7 9.7