condition mean min max ZT0-3 4.780885 4.780885 4.780885 ZT4-7 3.27431 3.27431 3.27431 ZT8-11 8.12198 8.12198 8.12198 ZT12-15 11.394400000000001 11.394400000000001 11.394400000000001 ZT16-19 8.85403 8.85403 8.85403 ZT20-23 6.9963049999999996 6.9963049999999996 6.9963049999999996