condition mean min max ZT0-3 2.15078 2.15078 2.15078 ZT4-7 1.61903 1.61903 1.61903 ZT8-11 4.260395 4.260395 4.260395 ZT12-15 4.3017900000000004 4.3017900000000004 4.3017900000000004 ZT16-19 2.4464550000000003 2.4464550000000003 2.4464550000000003 ZT20-23 2.9982499999999996 2.9982499999999996 2.9982499999999996