condition mean min max ZT0-3 5.574125 5.574125 5.574125 ZT4-7 4.329615 4.329615 4.329615 ZT8-11 4.912665 4.912665 4.912665 ZT12-15 5.9178 5.9178 5.9178 ZT16-19 7.714205 7.714205 7.714205 ZT20-23 5.800825 5.800825 5.800825