condition mean min max ZT0-3 2.20369275 2.010675 2.3967105 ZT4-7 3.327795 3.327795 3.327795 ZT8-11 2.8459149999999998 2.8459149999999998 2.8459149999999998 ZT12-15 0 0 0 ZT16-19 1.581255 1.581255 1.581255 ZT20-23 0.991838 0.991838 0.991838