condition mean min max ZT0-3 15.887861 15.887861 15.887861 ZT4-7 17.768922500000002 17.768922500000002 17.768922500000002 ZT8-11 19.29434 19.29434 19.29434 ZT12-15 19.2021095 19.2021095 19.2021095 ZT16-19 27.7794955 27.7794955 27.7794955 ZT20-23 25.163189 25.163189 25.163189