condition mean min max ZT0-3 1.764485 1.62272 1.90625 ZT4-7 1.8769550000000002 1.8769550000000002 1.8769550000000002 ZT8-11 0.833829 0.833829 0.833829 ZT12-15 0 0 0 ZT16-19 1.28692 1.28692 1.28692 ZT20-23 1.5521500000000001 1.5521500000000001 1.5521500000000001