condition mean min max ZT0-3 4.4417480000000005 3.027455 7.235645000000001 ZT4-7 4.06936 4.06936 4.06936 ZT8-11 1.1946455 1.1946455 1.1946455 ZT12-15 0.75583875 0.1981625 1.313515 ZT16-19 5.062775 5.062775 5.062775 ZT20-23 8.59497 8.59497 8.59497