condition mean min max ZT0-3 7.646940000000001 7.048310000000001 8.24557 ZT4-7 3.44671 3.44671 3.44671 ZT8-11 2.121715 2.121715 2.121715 ZT12-15 0 0 0 ZT16-19 5.57277 5.57277 5.57277 ZT20-23 6.69585 6.69585 6.69585