condition mean min max ZT0-3 0.7786666666666666 0.0 2.336 ZT4-7 1.06352 1.06352 1.06352 ZT8-11 6.710165 6.710165 6.710165 ZT12-15 5.25318 4.760315 5.7460450000000005 ZT16-19 5.292875 5.292875 5.292875 ZT20-23 4.79438 4.79438 4.79438