condition mean min max ZT0-3 16.440143 16.440143 16.440143 ZT4-7 14.6690145 14.6690145 14.6690145 ZT8-11 21.642011500000002 21.642011500000002 21.642011500000002 ZT12-15 20.6990015 20.6990015 20.6990015 ZT16-19 42.9411015 42.9411015 42.9411015 ZT20-23 47.6276705 47.6276705 47.6276705