condition mean min max ZT0-3 23.6 23.6 23.6 ZT4-7 2.6 2.6 2.6 ZT8-11 2.6 2.6 2.6 ZT12-15 8.6 8.6 8.6 ZT16-19 5.9 5.9 5.9 ZT20-23 7.3 7.3 7.3