condition mean min max ZT0-3 16.094023 16.094023 16.094023 ZT4-7 16.9570375 16.9570375 16.9570375 ZT8-11 23.459490000000002 23.459490000000002 23.459490000000002 ZT12-15 14.4545055 14.4545055 14.4545055 ZT16-19 17.6500585 17.6500585 17.6500585 ZT20-23 19.089487 19.089487 19.089487