condition mean min max ZT0-3 6.98571 6.5657 7.4057200000000005 ZT4-7 4.775825 4.775825 4.775825 ZT8-11 4.73787 4.73787 4.73787 ZT12-15 0 0 0 ZT16-19 6.856484999999999 6.856484999999999 6.856484999999999 ZT20-23 5.65469 5.65469 5.65469