condition mean min max ZT0-3 34.095621 34.095621 34.095621 ZT4-7 24.562539 24.562539 24.562539 ZT8-11 16.34045 16.34045 16.34045 ZT12-15 16.654909 16.654909 16.654909 ZT16-19 12.8898635 12.8898635 12.8898635 ZT20-23 14.1964695 14.1964695 14.1964695