condition mean min max ZT0-3 3.8 3.8 3.8 ZT4-7 1.1 1.1 1.1 ZT8-11 6.3999999999999995 6.3999999999999995 6.3999999999999995 ZT12-15 11.2 11.2 11.2 ZT16-19 17.05 17.05 17.05 ZT20-23 3.8 3.8 3.8