condition mean min max ZT0-3 9.973858333333332 7.791475 11.6099 ZT4-7 10.084425 10.084425 10.084425 ZT8-11 10.547550000000001 10.547550000000001 10.547550000000001 ZT12-15 14.836625 14.10465 15.5686 ZT16-19 13.268699999999999 13.268699999999999 13.268699999999999 ZT20-23 13.9362 13.9362 13.9362