condition mean min max ZT0-3 11.9 11.9 11.9 ZT4-7 1.1 1.1 1.1 ZT8-11 15.05 15.05 15.05 ZT12-15 7.65 7.65 7.65 ZT16-19 4.9 4.9 4.9 ZT20-23 11.55 11.55 11.55