condition mean min max ZT0-3 9.4 9.4 9.4 ZT4-7 4.4 4.4 4.4 ZT8-11 3.05 3.05 3.05 ZT12-15 5.050000000000001 5.050000000000001 5.050000000000001 ZT16-19 5.85 5.85 5.85 ZT20-23 5.75 5.75 5.75