condition mean min max ZT0-3 3.188005 3.188005 3.188005 ZT4-7 2.773275 2.773275 2.773275 ZT8-11 2.41883 2.41883 2.41883 ZT12-15 2.4942349999999998 2.4942349999999998 2.4942349999999998 ZT16-19 4.261089999999999 4.261089999999999 4.261089999999999 ZT20-23 2.95606 2.95606 2.95606