condition mean min max ZT0-3 21.0 21.0 21.0 ZT4-7 2.6 2.6 2.6 ZT8-11 10.95 10.95 10.95 ZT12-15 5.5 5.5 5.5 ZT16-19 6.4 6.4 6.4 ZT20-23 5.45 5.45 5.45