condition mean min max ZT0-3 22.7 22.7 22.7 ZT4-7 6.4 6.4 6.4 ZT8-11 16.95 16.95 16.95 ZT12-15 3.6 3.6 3.6 ZT16-19 14.2 14.2 14.2 ZT20-23 3.4000000000000004 3.4000000000000004 3.4000000000000004