condition mean min max ZT0-3 5.0757375 4.7487449999999995 5.40273 ZT4-7 4.506785000000001 4.506785000000001 4.506785000000001 ZT8-11 12.0266 12.0266 12.0266 ZT12-15 0 0 0 ZT16-19 11.268699999999999 11.268699999999999 11.268699999999999 ZT20-23 9.038385 9.038385 9.038385