condition mean min max ZT0-3 8.669451 8.669451 8.669451 ZT4-7 9.093717999999999 9.093717999999999 9.093717999999999 ZT8-11 9.110147000000001 9.110147000000001 9.110147000000001 ZT12-15 9.004766499999999 9.004766499999999 9.004766499999999 ZT16-19 8.749022499999999 8.749022499999999 8.749022499999999 ZT20-23 8.282508499999999 8.282508499999999 8.282508499999999