condition mean min max ZT0-3 15.7 15.7 15.7 ZT4-7 25.2 25.2 25.2 ZT8-11 24.4 24.4 24.4 ZT12-15 23.6 23.6 23.6 ZT16-19 15.95 15.95 15.95 ZT20-23 9.0 9.0 9.0