condition mean min max ZT0-3 5.330445 5.330445 5.330445 ZT4-7 4.017110000000001 4.017110000000001 4.017110000000001 ZT8-11 3.0424049999999996 3.0424049999999996 3.0424049999999996 ZT12-15 4.1511949999999995 4.1511949999999995 4.1511949999999995 ZT16-19 4.26285 4.26285 4.26285 ZT20-23 4.882125 4.882125 4.882125