condition mean min max ZT0-3 8.2601225 8.088284999999999 8.43196 ZT4-7 8.828635 8.828635 8.828635 ZT8-11 11.75965 11.75965 11.75965 ZT12-15 0 0 0 ZT16-19 11.6632 11.6632 11.6632 ZT20-23 11.56575 11.56575 11.56575