condition mean min max ZT0-3 11.55 11.55 11.55 ZT4-7 21.1 21.1 21.1 ZT8-11 21.9 21.9 21.9 ZT12-15 34.45 34.45 34.45 ZT16-19 16.2 16.2 16.2 ZT20-23 34.2 34.2 34.2