condition mean min max ZT0-3 3.5047575 3.3247299999999997 3.684785 ZT4-7 7.975664999999999 7.975664999999999 7.975664999999999 ZT8-11 30.049 30.049 30.049 ZT12-15 0 0 0 ZT16-19 14.13915 14.13915 14.13915 ZT20-23 6.617005 6.617005 6.617005