condition mean min max ZT0-3 3.35 3.35 3.35 ZT4-7 20.1 20.1 20.1 ZT8-11 13.7 13.7 13.7 ZT12-15 11.05 11.05 11.05 ZT16-19 19.4 19.4 19.4 ZT20-23 8.15 8.15 8.15