condition mean min max ZT0-3 6.565945 6.565945 6.565945 ZT4-7 4.97867 4.97867 4.97867 ZT8-11 6.942425 6.942425 6.942425 ZT12-15 6.565795 6.565795 6.565795 ZT16-19 6.57593 6.57593 6.57593 ZT20-23 5.690614999999999 5.690614999999999 5.690614999999999