condition mean min max ZT0-3 394.114819 394.114819 394.114819 ZT4-7 246.47391900000002 246.47391900000002 246.47391900000002 ZT8-11 197.91283399999998 197.91283399999998 197.91283399999998 ZT12-15 230.687387 230.687387 230.687387 ZT16-19 587.7476565000001 587.7476565000001 587.7476565000001 ZT20-23 431.329472 431.329472 431.329472