condition mean min max ZT0-3 8.2485525 7.292735 9.20437 ZT4-7 7.15853 7.15853 7.15853 ZT8-11 7.5688949999999995 7.5688949999999995 7.5688949999999995 ZT12-15 0 0 0 ZT16-19 9.873425000000001 9.873425000000001 9.873425000000001 ZT20-23 9.796595 9.796595 9.796595