condition mean min max ZT0-3 29.86035 29.86035 29.86035 ZT4-7 21.5228 21.5228 21.5228 ZT8-11 27.40475 27.40475 27.40475 ZT12-15 32.54175 32.54175 32.54175 ZT16-19 37.00790000000001 37.00790000000001 37.00790000000001 ZT20-23 31.8607 31.8607 31.8607