condition mean min max ZT0-3 24.2553 24.2553 24.2553 ZT4-7 27.8806 27.8806 27.8806 ZT8-11 6.714635 6.714635 6.714635 ZT12-15 2.828355 2.828355 2.828355 ZT16-19 6.71557 6.71557 6.71557 ZT20-23 12.4948 12.4948 12.4948