condition mean min max ZT0-3 12.762777499999999 11.322705 14.20285 ZT4-7 7.983414999999999 7.983414999999999 7.983414999999999 ZT8-11 7.367085 7.367085 7.367085 ZT12-15 0 0 0 ZT16-19 12.743235000000002 12.743235000000002 12.743235000000002 ZT20-23 15.20135 15.20135 15.20135