condition mean min max ZT0-3 4.7586025 4.4805600000000005 5.036645 ZT4-7 7.29612 7.29612 7.29612 ZT8-11 3.43655 3.43655 3.43655 ZT12-15 0 0 0 ZT16-19 6.361045 6.361045 6.361045 ZT20-23 6.0123999999999995 6.0123999999999995 6.0123999999999995