condition mean min max ZT0-3 6.99944 6.731305000000001 7.267575 ZT4-7 7.122635 7.122635 7.122635 ZT8-11 6.39825 6.39825 6.39825 ZT12-15 0 0 0 ZT16-19 3.81166 3.81166 3.81166 ZT20-23 5.910305 5.910305 5.910305