condition mean min max ZT0-3 16.746673 16.746673 16.746673 ZT4-7 15.4504165 15.4504165 15.4504165 ZT8-11 16.381866000000002 16.381866000000002 16.381866000000002 ZT12-15 15.2586595 15.2586595 15.2586595 ZT16-19 16.829815 16.829815 16.829815 ZT20-23 16.310647 16.310647 16.310647