condition mean min max ZT0-3 12.85 12.85 12.85 ZT4-7 5.4 5.4 5.4 ZT8-11 16.05 16.05 16.05 ZT12-15 11.6 11.6 11.6 ZT16-19 24.9 24.9 24.9 ZT20-23 21.549999999999997 21.549999999999997 21.549999999999997