condition mean min max ZT0-3 19.7 19.7 19.7 ZT4-7 2.9 2.9 2.9 ZT8-11 13.9 13.9 13.9 ZT12-15 11.5 11.5 11.5 ZT16-19 7.1 7.1 7.1 ZT20-23 4.45 4.45 4.45