condition mean min max ZT0-3 1.84201 1.314025 2.369995 ZT4-7 1.5351650000000001 1.5351650000000001 1.5351650000000001 ZT8-11 4.0668050000000004 4.0668050000000004 4.0668050000000004 ZT12-15 0 0 0 ZT16-19 3.551665 3.551665 3.551665 ZT20-23 2.5956 2.5956 2.5956