condition mean min max ZT0-3 2.49641 2.49641 2.49641 ZT4-7 0.7813635 0.7813635 0.7813635 ZT8-11 2.03124 2.03124 2.03124 ZT12-15 3.4977400000000003 3.4977400000000003 3.4977400000000003 ZT16-19 4.544145 4.544145 4.544145 ZT20-23 2.533875 2.533875 2.533875