condition mean min max ZT0-3 18.166316666666667 16.98635 20.477800000000002 ZT4-7 16.829250000000002 16.829250000000002 16.829250000000002 ZT8-11 16.53905 16.53905 16.53905 ZT12-15 17.026275 15.838949999999999 18.2136 ZT16-19 12.8703 12.8703 12.8703 ZT20-23 12.9777 12.9777 12.9777