condition mean min max ZT0-3 6.3299375 5.95146 6.7084150000000005 ZT4-7 3.37803 3.37803 3.37803 ZT8-11 2.65437 2.65437 2.65437 ZT12-15 0 0 0 ZT16-19 4.982525 4.982525 4.982525 ZT20-23 5.9545200000000005 5.9545200000000005 5.9545200000000005