condition mean min max ZT0-3 19.88897 19.88897 19.88897 ZT4-7 19.4204325 19.4204325 19.4204325 ZT8-11 15.639846499999999 15.639846499999999 15.639846499999999 ZT12-15 15.2080525 15.2080525 15.2080525 ZT16-19 14.983658499999999 14.983658499999999 14.983658499999999 ZT20-23 16.184516 16.184516 16.184516