condition mean min max ZT0-3 4.949999999999999 4.949999999999999 4.949999999999999 ZT4-7 9.3 9.3 9.3 ZT8-11 3.05 3.05 3.05 ZT12-15 19.0 19.0 19.0 ZT16-19 5.7 5.7 5.7 ZT20-23 5.65 5.65 5.65