condition mean min max ZT0-3 2.4746125125000002 1.9514505830000002 2.997774442 ZT4-7 6.7628136332499995 5.5761208595 7.949506406999999 ZT8-11 7.89153325075 7.4881882285 8.294878273 ZT12-15 2.70944514175 1.7627487455 3.6561415379999995 ZT16-19 1.1640858552500002 1.0005404365000001 1.327631274 ZT20-23 0.61029394425 0.4983271435 0.722260745