condition mean min max ZT0-3 136.253409 136.253409 136.253409 ZT4-7 120.61364 120.61364 120.61364 ZT8-11 102.8525535 102.8525535 102.8525535 ZT12-15 115.2204945 115.2204945 115.2204945 ZT16-19 109.6162795 109.6162795 109.6162795 ZT20-23 122.5123465 122.5123465 122.5123465