condition mean min max ZT0-3 15.002556 15.002556 15.002556 ZT4-7 19.2671 19.2671 19.2671 ZT8-11 19.789441500000002 19.789441500000002 19.789441500000002 ZT12-15 19.17951 19.17951 19.17951 ZT16-19 18.86781 18.86781 18.86781 ZT20-23 19.3347015 19.3347015 19.3347015