condition mean min max ZT0-3 13.036099 13.036099 13.036099 ZT4-7 12.089888 12.089888 12.089888 ZT8-11 14.4239775 14.4239775 14.4239775 ZT12-15 13.698335499999999 13.698335499999999 13.698335499999999 ZT16-19 12.586731499999999 12.586731499999999 12.586731499999999 ZT20-23 13.38774 13.38774 13.38774