condition mean min max ZT0-3 5.050000000000001 5.050000000000001 5.050000000000001 ZT4-7 3.5 3.5 3.5 ZT8-11 3.55 3.55 3.55 ZT12-15 7.1 7.1 7.1 ZT16-19 4.45 4.45 4.45 ZT20-23 4.949999999999999 4.949999999999999 4.949999999999999